D.D. Onduru, P. Snijders, F.N. Muchena, B. Wouters, A. De Jager, L. Gachimbi and G.N. Gachini
International Journal of Agricultural Research 3 ( 3 ): 166 - 187 , 2008
D. D. Onduru, A. De Jager, F. N. Muchena, L. Gachimbi and G. N. Gachini
International Journal of Agricultural Research 2 ( 5 ): 426 - 439 , 2007