1. Buahin, G. K. A. and Edwards, C.A. (1965): The recolonisation of sterilised soil by arthropods. Rep. Rothamsted Expfl Stn. 1964, 185–186.
2. Edwards, C.A. and Lofty, J.R. (1969) : The influence of agricultural practice on soil microarthropod populations. In: The Soil Ecosystem, Systematics Assoc., Publ. 8., Ed. J.G. Sheals, 237–47.
3. Evans, A.C. and Guild, W. J. McL. (1948): Studies on the relationships between earthworms and soil fertility. V. Field populations. Ann. Appl. Biol. 35(4) 485–93.
4. Graff, O. (1953): Investigations in soil zoology with special reference to the terricole Oligochaeta. Z. Pfl. Ernähr. Düng. 61, 72–7.
5. Hopp, H. and Hopkins, M. T. (1946) : The effect of cropping systems on the winter populations of earthworms. J.Soil Water Conserv. 1(1), 85–8.