البحث العاشر
10- Mohamed M. Mousa and A. Kaltayev, Homotopy perturbation method for solving nonlinear differential-difference equations, Zeitschrift für Naturforschung A (A Journal of Physical Sciences), Vо1. 65a № 6/7 (2010), 511–517.
Abstract link: https://www.degruyter.com/view/j/zna.2010.65.issue-6-7/zna-2010-6-705/zna-2010-6-705.xml?format=INT