C.Y. Abasi, A.A. Abia and J.C. Igwe
Environmental Research Journal 5 ( 3 ): 104 - 113 , 2011
A.A. Abia, O.B. Didi and E.D. Asuquo
Journal of Applied Sciences 6 ( 12 ): 2549 - 2556 , 2006
J.C. Igwe, O.F. Mbonu and A.A. Abia
Journal of Applied Sciences 7 ( 19 ): 2840 - 2847 , 2007