Ghalambaz, M. , Noghrehabadi, A. , Behrang, M. , Assareh, E. , Ghanbarzadeh, A. , N.Hedayat, N.. "A Hybrid Neural Network and Gravitational Search Algorithm (HNNGSA) Method to Solve well known Wessinger's Equation". World Academy of Science, Engineering and Technology, Open Science Index 49, International Journal of Mechanical and Mechatronics Engineering, (2011), 5(1), 147 - 151.