1. Bascomb, C. L., 1974, Personal communication.
2. Crampton, C. L., 1972, Soils of the Vale of Glamorgan, Memoirs of the Soil Survey of England and Wales, p. 75.
3. Fouweather, C., May, R. W., and Porter, J., 1975 (to be published).
4. Hartnup, R., and Jarvis, R. A., 1973, Soils of the Castleford Area of Yorkshire, Special Survey No. 8, Soil Survey of England and Wales, p. 82.
5. Jarvis, M. G., 1973, Soils of the Wantage and Abingdon District, Memoirs of the Soil Survey of England and Wales, p. 188.