1. Davies, J. N., Steam sterilization studies. Rep. Glasshouse Crops Research Inst. 1954/55, 70?79 (1957).
2. Dyakova, E. V., The relation of clover, lucerne and other feed grasses to an excess of available manganese in podzols. Dokl. Akad. S-Kh. Nauk No.9, 14?20 (1950).
3. Harward, M. E., Jackson, W. A., Lott, W. L. and Mason, D. D., Effect of Al, Fe and Mn upon the growth and composition of lettuce. Proc. Am. Soc. Hort. Sci.66 261?266 (1955).
4. Heslep, J. M., A study of the infertility of two acid soils. Soil Sci.72 67?80 (1951).
5. Lamb, J. G. D., A case of manganese toxicity affecting a cold house tomato crop. Irish J. Agr. Research1 17?20 (1961).