.245
a	Fertilizer nitrogen use efficiency and nutrient uptake by Maize (Zea mays L.) in vertisols in Kenya.
h	Book
.100
a	Sigunga Dalmas O.
.005
a	00000000000000
.260
a	Wageningen: Landbouwuniversiteit te Wageningen, 1997.
b
c	2000
.084
a	581.192 482 Hei
.300
a	xi, 205 hlm.
b	tab., 24 cm.
c	xi, 205 hlm.; tab., 24 cm.
.336
a	Book