Shirlaw, D. (1962). Soil fertility and field methods of analysis: A guide for agricultural students and advisers, gardeners and horticulturalists. Cassell & company.
Dyfyniad Arddull ChicagoShirlaw, D.W.Gilchrist. Soil Fertility and Field Methods of Analysis: A Guide for Agricultural Students and Advisers, Gardeners and Horticulturalists. London: Cassell & company, 1962.
Dyfyniad MLAShirlaw, D.W.Gilchrist. Soil Fertility and Field Methods of Analysis: A Guide for Agricultural Students and Advisers, Gardeners and Horticulturalists. Cassell & company, 1962.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.