Journal of Modern Mathematics and Statistics 2 ( 2 ): 65 - 69 , 2008
Research Journal of Applied Sciences 2 ( 3 ): 307 - 309 , 2007
Umar Mallam Abdulkarim and H.S. Ndakwo
Research Journal of Applied Sciences 2 ( 4 ): 367 - 371 , 2007
Research Journal of Applied Sciences 2 ( 5 ): 595 - 599 , 2007
Research Journal of Applied Sciences 2 ( 6 ): 673 - 676 , 2007