1. Sulphur in Northern Nigeria soils. I. The effects of cultivation and fertilizers on total S and sulphate patterns in soil profiles;Bromfield;J. agric. Sci. Camb.,1972
2. Die Schwelfelversorgung der westdeutschen Landwirtschaft;Buchner;Landwirtsch. Forsch.,1958
3. Accessions of sulphur in the rainwater at Perth and Nedlands, Western Australia;Drover;J. Roy. Soc. W. Aust.,1960
4. Sulphur and nitrogen in forest soils of East Africa;Hesse;Plant and Soil,1957