C. I. Duruigbo, J. C. Obiefuna and E. U. Onweremadu
International Journal of Soil Science 2 ( 2 ): 154 - 158 , 2007
E. U. Onweremadu, C. C. Opara, U. Nkwopara, C. I. Duruigbo and I. I. Ibeawuchi
International Journal of Soil Science 1 ( 3 ): 251 - 257 , 2006
G. O. Ihejirika, M. I. Nwufo, C. I. Duruigbo, E. U. Onwerenadu, O. P. Obilo, E. R. Onuoha and K. O. Ogbede
Journal of Plant Sciences 1 ( 4 ): 374 - 377 , 2006