Share This Article:

Evolution of the Hoabinhian Techno-Complex of Tam Hang Rock Shelter in Northeastern Laos

Abstract Full-Text HTML XML Download Download as PDF (Size:5555KB) PP. 140-157
DOI: 10.4236/ad.2015.34013    3,786 Downloads   4,577 Views   Citations

ABSTRACT

Tam Hang rock shelter was excavated in 1934 by the French geologist Jacques Fromaget who discovered 13 skeletons and a lot of stone tools. But after the second War World, the lithic assemblages were lost. Then the site was forgotten since 2003, when the department of archaeology of the Lao Ministry of Culture relocated it and made with a French team a new prospection. In 2007 and after seven campaigns of excavations, a lot of archaeological materials had been found in two new areas opened at Tam Hang South and Tam Hang Central. More than 9000 specimens of stone have been found. This article proposes to give a new approach of the whole stratigraphy with C14 dating. It also makes a characterization of the lithic assemblage which belongs to the Hoabinhian techno-complex.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Patole-Edoumba, E. , Duringer, P. , Richardin, P. , Shackelford, L. , Bacon, A. , Sayavongkhamdy, T. , Ponche, J. and Demeter, F. (2015) Evolution of the Hoabinhian Techno-Complex of Tam Hang Rock Shelter in Northeastern Laos. Archaeological Discovery, 3, 140-157. doi: 10.4236/ad.2015.34013.

References

[1] Arambourg, C., & Fromaget, J. (1938). Le gisement quaternaire de Tam Nang (Chaine Annamitique septentrionale). Sa stratigraphie et ses faunes. Comptes Rendus de l’AcadEmie des Sciences, 203, 793-795.
[2] Aung, Th. (1969). The “Neolithic” Culture of the Padah-Lin Caves. Journal of Burma Research Society, 52, 9-23.
[3] Bacon, A., Demeter, F., Duringer, Ph., Patole-Edoumba, E., Sayavongkhamdy, Th, Coupey, A. M., & Shackelford, L. (2012). Les sites de Tam Hang, Nam Lot et Tam Pa Ling au nord du Laos: Des gisements a vertebres du pleistocene aux origines des hommes modernes. Paris: CNRS Editions.
[4] Bacon, A.-M., Demeter, F., Tougard, C., De Vos, J., Sayavongkhamdy, T., Antoine, P.-O., Bouasisengpaseuth, B., & Sichanthongtip, P. (2008). RedEcouverte d’une faune plEistocene dans les remplissages karstiques de Tam Hang au Laos: premiers rEsultats. Comptes Rendus Palevol, 7, 277-288.
http://dx.doi.org/10.1016/j.crpv.2008.03.009
[5] Bacon, A.-M., Duringer, P., Antoine, P-O., Demeter, F., Shackelford, L., Sayavongkhamdy, T., Sichanthongtip, P., Khamdalavong, P., Nokhamaomphu, S., Sysuphanh, V., Patole-Edoumba, E., Chabaux, F., & Pelt, E. (2011). The Middle Pleistocene Mammalian Fauna from Tam Hang Karstic Deposit, Northern Laos: New Data and Evolutionary Hypothesis. Quaternary International, 245, 315-332.
http://dx.doi.org/10.1016/j.quaint.2010.11.024
[6] Bellwood, P. (1993). Cultural and Biological Differentiation in Peninsular Malaysia: The Last 10,000 Years. Asian Perspectives, 32, 37-60.
[7] Bellwood, P. (1997). Prehistory of Indo-Malaysian Archipelago. Honolulu: University of Hawai Press.
[8] Binh, N. (1991). Back to the Periodization of Hoabinhian in Vietnam. REcentes recherches en archEologie en Thailande. Bangkok: Silpakorn University.
[9] Boeda, E. (1997). TechnogEnese des systemes de production lithique au PalEolithique infErieur et moyen en Europe occidentale et au Proche-Orient (Vol. 2). Paris : UniversitE de Paris X-Nanterre.
[10] Boeda, E. (2001). DEtermination des unitEs techno-fonctionnelles de pieces bifaciales provenant de la couche acheulEenne C’3 base du site de Barbas. In D. Cliquet (Ed.), Les industries a outils bifaciaux du PalEolithique moyen d’Europe occidentale (pp. 51-75). Liege: ERAUL.
[11] Boriskovsky, P. (1969). Vietnam in Primeval Times. Sovietic Anthropological Archaeology, 8, 214-257.
http://dx.doi.org/10.2753/AAE1061-19590803214
[12] Bourguignon, L. (1997). Le MoustErien de type Quina: Nouvelle dEfinition d’une entitE technique. PhD Thesis, Nanterre: UniversitE Paris X.
[13] Bowdler, S. (2008). Hoabinhian and Non-Hoabinhian. In J. P. Pautreau, A. S. Coupey, V. Zeitoun, & E. Rambault (Eds.), From Homo Erectus to the Living Traditions (pp. 59-66). Chiang Mai: Siam Ratana Ltd. Part.
[14] Colani, M. (1929a). Quelques palEolithes hoabinhiens typiques de l’abri-sous-roche de Lang Kay. Bulletin de l’Ecole Francaise d’Extreme-Orient, 26, 353-384.
[15] Colani, M. (1929b). Quelques stations hoabinhiennes (note prEliminaire). Bulletin de l’Ecole Francaise d’Extreme-Orient, 29, 261-272.
http://dx.doi.org/10.3406/befeo.1929.3240
[16] Colani, M. (1932). Champs de jarres monolithiques et de pierres funEraires du Tran-Ninh (Haut Laos). In Congres des prEhistoriens d’Extreme-Orient (pp. 103-128). Hanoi: Imprimeried’Extreme-Orient.
[17] Colani, M. (1935). MEgalithes du Haut-Laos (Hua Pan, Tran Ninh). Paris: Ecole Francaise d’Extreme-Orient.
[18] Cook, C. G., & Jones R. T. (2012). Palaeoclimate Dynamics in Continental Southeast Asia over the Last ~30,000 Cal yrs BP. Palaeogeography, Palaeoclimatology, Palaeoecology, 339-341, 1-11.
http://dx.doi.org/10.1016/j.palaeo.2012.03.025
[19] Demeter, F., Sayavongkhamdy, T., Patole-edoumba, E., Coupey, A. S., Bacon, A.-M., De Vos, J., Tougard, C., Bouasisengpaseuth, B., Sichanthongtip, P., & Duringer, P. (2010). Tam Hang Rockshelter: Preliminary Study of a Prehistoric Site in Northern Laos. Asian Perspectives, 48, 291-308.
http://dx.doi.org/10.1353/asi.2009.0000
[20] Demeter, F., Shackelford, L., Bacon, A. M., Duringer, P., Westawa, K., Sayavongkhamd, T., Braga, J., Sichanthongtip, P., Khamdalavong, P., Ponche, J. L., Wang, H., Lundstrom, C., Patole-Edoumba, E., & Karpoff, A.-M. (2012). Anatomically Modern Human in Southeast Asia (Laos) by 46 ka. Proceedings of the National Academy of Sciences of the United States of America, 109, 14375-14380.
http://dx.doi.org/10.1073/pnas.1208104109
[21] Dennell, R. W. (2009). The Palaeolithic Settlement of Asia. New York: Cambridge University Press.
[22] Dunn, F. L. (1964). Excavations at Gua Kecchil, Pahang. Journal of the Malaysian Branch Royal Asiatic Society, 37, 87-124.
[23] Forestier, F., Sophady, H., Puaud, S., Celiberti, V., Frere, S., Zeitoun, V., Mourer-ChauvirE, C., Mourer, R., Than, H., & Billault, L. (2015). The Hoabinhian from Laang Spean Cave in Its Stratigraphic, Chronological, Typo-Technological and Environmental Context (Cambodia, Battambang Province). Journal of Archaeological Science, 3, 194-206.
http://dx.doi.org/10.1016/j.jasrep.2015.06.008
[24] Forestier, H. (2005). Le site de Togi Ndrawa, ile de Nias, Sumatra nord: Les premieres traces d’une occupation hoabinhienne en grotte en IndonEsie. Comptes Rendus Palevol, 4, 727-733.
http://dx.doi.org/10.1016/j.crpv.2005.08.004
[25] Forestier, H. (2010). Hoabinhian: Flake Stone in Southeast Asia, Mainland to Archipelago. Journal of the Korean Palaeolithic Society, 22, 67-77.
[26] Forestier, H., Zeitoun, V., Winayalai, C., & MEtais, C. (2013). The Open-Air Site of Huai Hin (North-Western Thailand): Chronological Perspectives for the Hoabinhian. Comptes Rendus Palevol, 12, 45-55.
http://dx.doi.org/10.1016/j.crpv.2012.09.003
[27] Fromaget, J. (1934). Observations et rEflexions sur la gEologie stratigraphique et structurale de l’Indochine. Bulletin du Service gEologique d’Indochine, 4, 101-164.
[28] Fromaget, J. (1936). Sur la stratigraphie des formations rEcentes de la Chaine annamitique septentrionale et sur l’existence de l’homme dans le Quaternaire infErieur de cette partie de l’Indochine. Compte Rendu de L’AcadEmie des Sciences de Paris, 16, 738-741.
[29] Fromaget, J. (1937a). Etudes gEologiques sur le Nord-Ouest du Tonkin et le Nord du Haut Laos-premiere partie. Bulletin du Service gEologique d’Indochine, 23, 101-164.
[30] Fromaget, J. (1937b). Apercu sur la stratigraphie et l’anthropologie prEhistorique des formations rEcentes dans la Chaine annamitique et le Haut-Laos. In Compte rendu de la douzieme session du Congres prEhistorique de France (pp. 785-798). Toulouse-Foix: SociEtE PrEhistorique de France.
[31] Fromaget, J. (1940a). Les rEcentes dEcouvertes anthropologiques dans les formations prEhistoriques de la Chaine annamitique. In Proceedings of the Third Congress of Prehistorians of the Far East (pp. 51-59). Singapore: F.N. Chasen and M.W.F. Tweedie.
[32] Fromaget, J. (1940b). La stratigraphie des dEpots prEhistoriques de Tam Hang (Chaine annamitique septentrionale) et ses difficultEs. In Proceedings of the Third Congress of Prehistorians of the Far East (pp. 60-70). Singapore: F.N. Chasen and M.W.F. Tweedie.
[33] Fromaget, J. (1941). L’Indochine francaise, sa structure, ses roches, ses mines et leurs relations possibles avec la tectonique. Bulletin du Service gEologique d’Indochine, 26, 1-140.
[34] Fromaget, J. (1952). Etudes gEologiques sur le Nord-Ouest du Tonkin et le Nord du Haut-Laos-premiere partie. Bulletin du Service gEologique d’Indochine, 19, 1-198.
[35] Fromaget, J., & Saurin, E. (1936). Note prEliminaire sur les formations cEnozoiques et plus rEcentes de la Chaine annamitique septentrionale du haut Laos. Stratigraphie, prEhistoire, anthropologie. Bulletin du Service gEologique d’Indochine, 22, 7-48.
[36] Gaillard, C., Singh, M., & Malasse, A. D. (2011). Late Pleistocene to Early Holocene Lithic Industries in the Southern Fringes of the Himalaya. Quaternary International, 229, 112-122.
http://dx.doi.org/10.1016/j.quaint.2010.06.023
[37] Glover, I. C. (1977). The Hoabinhian: Hunter-Gatherers or Early Agriculturalists in South-East Asia? In J. V. S. Megaw (Ed.), Hunters, Pastoralists and Early Agriculturalists in South Asia (pp.145-166). Leicester: Leicester University Press.
[38] Gorman, C. (1971). The Hoabinhian and After: Subsistence Patterns in Southeast Asia during the Late Pleistocene and Early Recent Periods. World Archaeology, 2, 300-320.
http://dx.doi.org/10.1080/00438243.1971.9979482
[39] Gorman, C. (1972) Excavations at Spirit Cave, North Thailand: Some Interim Interpretations. Asian Perspectives, 13, 79-107.
[40] Gourou, P. (1948). La civilisation du vEgEtal. Indonesie, 1, 385-396.
[41] Hayden, B. (1977). Sticks and Stones and Ground Axes: The Upper Palaeolithic in Southeast Asia. In J. Alen, J. Golson, & R. Jones (Eds.), Sunda and Sahul (pp. 73-109). New York: Academic Press.
[42] Hazarika, M. (2012). Lithic Industries with Palaeolithic Elements in Northeast India. Quaternary International, 269, 48-58.
http://dx.doi.org/10.1016/j.quaint.2011.10.006
[43] Hazarika, M. (2013). Prehistoric Cultural Affinities between Southeast Asia, East Asia and Northeast India: An Exploration. In Unearthing Southeast Asia’s Past (pp. 16-25). Singapore: National University.
[44] Higham, C. (2014). Early Mainland in Southeast Asia: From First Humans to Angkor. Bangkok: River Books Press Dist A C.
[45] Higham, C., & Thosarat, R. (2004). The Excavation of Khok Phanom Di: A Prehistoric Site in Central Thailand (Vol. VII). London: The Society of Antiquaries of London.
[46] Hoang, X. C. (1989). Hoa Binh Culture in Vietnam. Hanoi: Manuscript.
[47] Hutterer, K. L. (1976). An Evolutionary Approach to Southeast Asian Cultural Sequence. Current Anthropology, 17, 221-242.
http://dx.doi.org/10.1086/201711
[48] Hutterer, K. L. (1977). Reinterpreting the Southeast Asian Palaeolithic. In J. Allen, J. Golson, & R. Jones (Eds.), Sunda and Sahul (pp. 31-72). New York: Academic Press.
[49] Lepot, M. (1993). Approche techno-fonctionnelle de l'outillage lithique moustErien: Essai de classification des parties actives en termes d'efficacitE technique. Application a la couche M2e sagittale de Grand Abri de la Ferrassie. MEmoire de maitrise, Nanterre: UniversitE Paris X.
[50] Mansuy, H. (1920). Contributions a l’Etude de l’Indochine. I. L’industrie de la pierre et du bronze dans la rEgion de Luang Prabang (Haut-Laos). Hanoi: Bulletin du Service gEologique d’Indochine 7.
[51] Marwick, B. (2008). What Attributes Are Important for the Measurement of Assemblage Reduction Intensity? Results from an Experimental Stone Artifact Assemblage with Relevance to the Hoabinhian of Mainland Southeast Asia. Journal of Archaeological Science, 35, 1189-1200.
http://dx.doi.org/10.1016/j.jas.2007.08.007
[52] Marwick, B. (2013). Multiple Optima in Hoabinhian Flaked Stone Artifact Palaeoeconomics and Palaeoecology at Two Archaeological Sites in Northwest Thailand. Journal of Anthropological Archaeology, 32, 553-564.
http://dx.doi.org/10.1016/j.jaa.2013.08.004
[53] Marwick, B., & Gagan M. K. (2011). Late Pleistocene Monsoon Variability in Northwest Thailand: An Oxygen Isotope Sequence from the Bivalve Margaritanopsis laosensis Excavated in Mae Hong Son Province. Quaternary Scientific Review, 30, 3088-3098.
http://dx.doi.org/10.1016/j.quascirev.2011.07.007
[54] Mattews, J. M. (1966). The Hoabinhian Affinities of Some Australian Assemblages. Archaeology and Physical Anthropology in Oceania, 1, 5-22.
[55] Maxwell, A. L. (2001). Holocene Monsoon Changes Inferred from Lake Sediment Pollen and Carbonate Records. Northeastern Cambodia. Quaternary Research, 56, 390-400.
[56] Maxwell, A. L. (2004). Fire Regime in North-Eastern Cambodian Monsoonal Forests, with a 9300-Year Sediment Charcoal Record. Journal of Biogeography, 31, 225-239.
http://dx.doi.org/10.1046/j.0305-0270.2003.01015.x
[57] Moser, J. (2001). Hoabinhian, Geographie und Chronologie eines steinzeitlichen Technocomplexes in Südostasien. Koln: Lindensoft.
[58] Moser, J. (2012). The Hoabinhian Definition—In the Past and Today: A Short Historical Review of Defining the Hoabinhian. In M. L. Tjoa-Bonatz, A. Reinecke, & D. Bonatz (Eds.), Crossing Borders: Selected Papers from the 13th International Conference of the European Association of Southeast Asian Archaeologists, Volume 1 (pp. 3-25). Singapore: National University of Singapore.
[59] Patole-Edoumba, E. (2012). L’industrie lithique de Tam Hang. In A. M. Bacon et al. (eds.), Les sites de Tam Hang, Nam Lot et Tam Pa Ling au nord du Laos: Des gisements a vertebres du Pleistocene aux origines des hommes modernes (pp. 65-100). Paris: CNRS Editions.
[60] Pavie, A. (1898-1919). Mission Pavie en Indochine 1879-1895 (11 Volumes). Paris: Leroux,
[61] Pawlik, A. (2015). Detecting Traits of Modern Behavioural through Microwear Analysis. A Case Study from the Philippines Terminal Pleistocene. In: Y. Kaifu, & M. Izuho (Eds.), Emergence and Diversity of Modern Human Behaviour in Palaeolithic Asia (pp. 182-200). College Station, TX: Texas A&M University Press.
[62] Penny, D. (2001). A 40,000 Year Palynological Record from North-East Thailand; Implications for Biogeography and Paleo-Environmental Reconstruction. Palaeogeography, Palaeoclimatology, Palaeoecology, 171, 97-128.
http://dx.doi.org/10.1016/S0031-0182(01)00242-5
[63] Penny, D. (2006). The Holocene History and Development of the Tonle Sap, Cambodia. Quaternary Science Reviews, 25, 310-322.
http://dx.doi.org/10.1016/j.quascirev.2005.03.012
[64] Pookajorn, S. (1990). Hoabinhian Cave Excavations in Ban Kao District, West Thailand. In E. Glover, & I. Glover (Eds.), Southeast Asian Archaeology 1986: Proceedings of the First Conference of the Association of Southeast Asian Archaeologists in Western Europe (pp. 11-28). Oxford: BAR.
[65] Pookajorn, S. (1996). Human Activities and Environmental Changes during the Late Pleistocene to Middle Holocene in Southern Thailand and Southeast Asia. In L. G. Straus et al. (Eds.), Humans at the End of the Lee Age (pp. 201-213). New York: Plenum Press.
http://dx.doi.org/10.1007/978-1-4613-1145-4_10
[66] Raymaekers, P. (2001). Prospection archEologique de la vallEe laotienne du fleuve MEkong. Volume II: The Artefacts. Oxford: Archeopress.
[67] Reed, K. E. (1997). Early Hominid Evolution and Ecological Change through the African Plio-Pleistocene. Journal of Human Evolution, 32, 289-322.
http://dx.doi.org/10.1006/jhev.1996.0106
[68] Santoni, M., Pautreau, J. P., & Prishanchit, S. (1990). Excavations at Obluang, Province of Chiang Mai, Thailand. In I. Glover, & E. Glover (Eds.), Southeast Asian Archaeology 1986: Proceedings of the First Conference of the Association of Southeast Asian Archaeologists in Western Europe (pp.37-54). London: BAR International Series 561.
[69] Saurin, E. (1935). Station nEolithique a Na Mou, Province de Luang Prabang (Haut-Laos) (Indochine francaise). Proceedings of the Congres prEhistorique de France, Onzieme session, Perigueux, Compte-rendu 11, 258-266.
[70] Saurin, E. (1951). Etudes gEologiques et prEhistoriques. Bulletin de la SociEtE des Etudes indochinoises, 26, 525-539.
[71] Saurin, E. (1966). Le mobilier prEhistorique de l’abri-sous-roche de Tam Pong (Haut Laos). Bulletin de la SociEtE des Etudes d’Indochine, 41, 106-118.
[72] Saurin, E. (1968). Station prEhistorique a ciel ouvert dans le massif du Pha Xieng Tong (Laos). Asian and Pacific Archaeology Series, 2, 86-95.
[73] Sayavongkhamdy, T., Bellwood, P., & Bulbeck, D. (2000). Recent Archaeological Research in Laos. Bulletin of the Indo-Pacific Prehistory Association, 19, 101-110.
[74] Schick, K. D., & Zhuan, D. (1993). Early Paleolithic of China and Eastern Asia. Evolutionary Anthropology, 2, 22-35.
http://dx.doi.org/10.1002/evan.1360020105
[75] Schoocongdej, R. (1996). Forager Mobility Organisation in Seasonal Tropical Environments: A Review from Lang Kamnan Cave, Western Thailand. Ann. Arbor: the University of Michigan.
[76] Sharma, T. C. (1988). Discovery of Hoabinhian Cultural Relics in Northeast India. In N. C. Ghosh, & S. Chakrabarty (Eds.), Adaptation and Other Essays: Proceedings of the Archaeological Conference (pp. 136-139). Vishwa Bharati, Shantiniketan: Research Publications.
[77] Solheim, W. G. (1970). Prehistoric Archaeology in Eastern Mainland Southeast Asia and the Philippines. Asian Perspectives, 13, 47-58.
[78] Solheim, W. G. (1974). The Hoabinhian and Island Southeast Asia. In R. B. Tantoco (Ed.), Proceedings of the First Regional Seminar on Southeast Asian Prehistory and Archaeology (pp.19-26). Manila: National Museum of the Philippines.
[79] Soni, A. S., Soni, V. S., & Rekhi, S. S. (2014). New Types of Stone Tools Found in Soanian Regime of the NW Sub-Himalayas of India. Human Biological Review, 3, 60-87.
[80] Sorensen, P. (1982). Hoabinhian and Woodworking in Thailand: A Research Paper in Anthropology for MSC. Philadelphia, PA: University of Pennsylvania.
[81] Soriano, S. (2001). Statut fonctionnel de l’outillage bifacial dans les industries du PalEolithique moyen: Propositions mEthodologiques. In D. Cliquet (Ed.), Les industries a outils bifaciaux du PalEolithique moyen d’Europe occidentale (pp. 77-83). Liege: ERAUL.
[82] Viet, N. (2004). Hoabinhian Food Strategy in Viet Nam. In V. Paz (Ed.), Southeast Asian Archaeology, Wilhelm G. Solheim II (pp. 442-462). Quezon City: Festschrift University of the Philippines Press.
[83] West, J., & Louys, J. (2007). Differentiating Bamboo from Stone Tool Cut Marks in the Zooarchaeological Record, with a Discussion on the Use of Bamboo Knives. Journal of Archaeological Science, 34, 512-518.
http://dx.doi.org/10.1016/j.jas.2006.06.007
[84] White, J. C., & Bouasisengpaseuth, B. (2008). Archaeology of the Middle Mekong: Introduction to the Luang Prabang Exploratory Survey. In Y. Goudineau, & M. Lorrillard (Eds.), Recherches Nouvelles sur le Laos.Ecole francaise d’Extreme Orient (pp. 37-52). Paris: E.F.E.O.
[85] White, J. C., & Gorman, C. (2004). Patterns in “Amorphous” Industries: The Hoabinhian Viewed through a Lithic Reduction Sequence. In V. Paz (Ed.), Southeast Asian Archaeology, Wilhelm G. Solheim II (pp. 411-441). Quezon City: Festschrift University of the Philippines Press.
[86] White, J. C., Lewis, H., Bouasisengpaseuth, B., Marwick, B., & Arrell, K. (2009). Archaeological Investigations in Northern Laos: New Contributions to Southeast Asian Prehistory. Antiquity, 83, 319.
[87] Yi, S., Lee, J., Kim, S., Yoo, Y., & Kim, D. (2008). New Data on the Hoabinhian: Investigations at Hang Cho Cave, Northern Vietnam. Bulletin of the Indo-Pacific Prehistory Association, 28, 73-79.
http://dx.doi.org/10.7152/bippa.v28i0.12018
[88] Yosef, O. B., Eren, B., Yuan, J., Cohen, J., & Li, Y. (2012). Were Bamboo Tools Made in Prehistoric Southeast Asia? An Experimental View from South China. Quaternary International, 269, 9-21.
http://dx.doi.org/10.1016/j.quaint.2011.03.026
[89] Zeitoun, V., Forestier, H., & Nakbunlung, S. (2008). PrEhistoires au sud du Triangle d’Or. Paris: Editions IRD.
[90] Zeitoun, V., Forestier, H. H., Pierret, A., Chiemsisouraj, C., Lorvankham, M., Latthagnot, A., Chanthamoungkhoun, T., & Norkhamsomphou, S. (2012). Multi-Millennial Occupation in Northwestern Laos: Preliminary Results of Excavations at the Ngeubhinh Mouxeu Rock-Shelter. Comptes Rendus Palevol, 11, 305-313.
http://dx.doi.org/10.1016/j.crpv.2011.11.001

  
comments powered by Disqus

Copyright © 2019 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.