1. Fagan, T. W., and Jones, H. T., Bull. Welsh Plant Breed. Sta., H, 3, 85 (1924).
2. Woodman, H. E., et al., J. Agric. Sci., 16, 205; 17, 209; 18, 206; 19, 236 (1926–29).
3. Whyte, R. O., “Crop Production and Environment” (Faber and Faber, London, 1946).
4. Hunt, I. V., J. Brit. Grass. Soc., 12, 127 (1957).
5. Watson, D. J., in “The Growth of Leaves” (Butterworths Scientific Publications, London, 1956).