1. The effect of soil drying on humus decomposition and nitrogen availability;Birch;Plant and Soil,1955
2. Measurement of microbial biomass phosphorus in soil;Brookes;Soil Biology and Biochemistry,1982
3. Phosphorus in the soil microbial biomass;Brookes;Soil Biology and Biochemistry,1984
4. Size and Turnover of the Microbial Biomass in Agricultural Soils, Laboratory and Field Measurement;Chaussod,1988
5. The water culture method for growing plants without soil;Hoagland;Californian Agricultural Experimental Station Circular,1938