1. Proctor J. M. (1958). Pea Growing Handbook (1958 edition). Pea Growing Research Organisation, p. 77.
2. Home Grown Threshed Peas Joint Committee (1954). Report for 1952–53, p. 34.
3. Home Grown Threshed Peas Joint Committee (1952). Second Progress Report on Field Experiments, 1950–51, p. 8.
4. Home Grown Threshed Peas Joint Committee (1950). Progress Report on Field Experiments, 1945–49, p. 9.