1. The potassium status of some English soils considered as a problem of energy relationships;Arnold;Proceedings of the Fertilizer Society,1962
2. Avery , B.W. Bullock , P. 1977 Mineralogy of clayey soils in relation to soil classification. Soil Survey Technical Monograph No. 10. Harpenden
3. Bullock , P. Loveland , P.J. 1974 Mineralogical Analysis. In Soil Survey Laboratory Methods B.W. Avery C.L. Bascomb 57 69 Technical Monograph of the Soil Survey No. 6, Harpenden
4. Some priorities for British soil science;Cooke;Journal of Soil Science,1979