Oil Palm Bulletin No. 17 (November 1988) p1 - 8
Oil Palm Yield Responses to P Fertilizer in Peninsular Malaysia
H.L. Foster, Ahmad Tarmizi Mohammed, Mohd. Tayeb Dolmat and Zin Z. Zakaria

Oil Palm Bulletin No. 3 (November 1981) p6 - 13
The determination of oil palm fertilizer requirements in Peninsular Malaysia Part I: Monitoring nutrient status
FOSTER, H L