D .T. Yaro, T. Kparmwang, B. A. Raji and V. O. Chude
International Journal of Soil Science 1 ( 3 ): 171 - 183 , 2006
C.C. Anyika, A. Ninyo and T. Kparmwang
Research Journal of Soil and Water Management 1 ( 2 ): 21 - 26 , 2010