فهرس المقالات Mehdi Yadollahi المقاله 1 - HGELS: A New Hybrid Algorithm Based on Gravitational Force for Solving Multiple Traveling Salesman Problems Touraj Mohammadpour Mehdi Yadollahi Amir Massoud Bidgoli Habib Esmaeelzadeh Rostam Journal of Advances in Computer Research , العدد 4 , السنة 7 , تابستان 2016