1. Nitrification;Alexander,1965
2. Determination and isotope ratio analysis of different forms of nitrogen in soils: 3. Exchangeable ammonium, nitrate and nitrite by extraction distillation methods;Bremner,1966
3. Winter changes in soil nitrate and exchangeable ammonium;Campbell;Canadian Journal of Soil Science,1970
4. The formation of nitrate from ammonium nitrogen in soils: 1. Effect of temperature;Frederick,1956
5. Influence of organic nitrogen compounds on nitrification in soil;Quastel;Nature,1949