1. Bartholomew , W.V. 1965. Soil Nitrogen, Amer. Soc. Agron., No. 10 Ser. Agronomy 285–306.
2. Bremner , J.M. 1965. Methods of Soil Analysis, Amer. Soc. Agron., No. 9 Ser. Agronomy 1324–1345.
3. Fiedler , H.J. and
Reissig , H. 1964. Lehrbuch der Bodenkunde, 236–237. Jena: VEB Gustav Fischer Verlag.
4. Gasser , J.K.E. 1969. Nitrogen and Soil Organic Matter, Techn. Bull. 15 71–77. London: Ministry of Agriculture, Fisheries and Food.
5. Mineralization of Organic Nitrogen in Soil