V. Juárez-Ramos, E. Salazar-López, M. Artacho, K. Chmielowiec, A. Riquelme, J. Fernández-Gómez, A. Fernández-Ramirez, A. Vicente de Haro, A. Miranda, M. Caballero, B. Machado, A. Hernández and E. Milán, "The Laughter of Ticklishness Is a Darwinian Feature Related to Empathy in Both Genders: Self-Esteem in Men and Sexism in Women,"
Open Journal of Medical Psychology, Vol. 3 No. 1, 2014, pp. 18-23. doi:
10.4236/ojmp.2014.31002.