Department of Mathematics, Faculty of Science, Gazi University, Ankara, Turkey
Institue of Science, Ahi Evran University, K?r?ehir, Turkey
Copyright © 2014 Serife Büyükköse, Sehri Gülçiçek Eski et al. This is
an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly cited.