%0 Journal Article %A A. Kamel, M. %A A. Abido, M. %A Moustafa Elshafei, %D 2018 %J Intelligent Automation \& Soft Computing %@ 2326-005X %V 24 %N 4 %P 795--805 %T Quad-Rotor Directional Steering System Controller Design Using Gravitational Search Optimization %M doi:10.1080/10798587.2017.1342414 %U http://www.techscience.com/iasc/v24n4/39806