O.E. Abdullahi and S.A. Onasanya
Journal of Applied Sciences 10 ( 19 ): 2198 - 2204 , 2010
M.F. Salman, M.O. Esere, J.A. Omotosho, O.E. Abdullahi and S.O. Oniyangi
Journal of Modern Mathematics and Statistics 4 ( 3 ): 96 - 100 , 2010
Pakistan Journal of Social Sciences 7 ( 3 ): 214 - 217 , 2010
The Social Sciences 5 ( 6 ): 514 - 519 , 2010