1. Alberda, Th., 1965. The influence of temperature, light intensity and nitrate concentration on dry-matter production and chemical composition of Lolium perenne. Neth J Agric Sci 13: 335–360.
2. Alberda, Th., 1966. The influence of reserve substances on dry-matter production after defoliation. Proc of the tenth International Grassland Congress: 140–147.
3. Baan Hofman, T. & G.C. Ennik, 1980. Investigation into plant characters affecting the competitive ability of perennial ryegrass (Lolium perenne L.) Neth J Agric Sci 28., 97–109.
4. Baker, A. & A. Younger, 1987. Factors affecting the leaf extension rate of perennial ryegrass in spring. Grass and Forage Science 42.: 381–390.
5. Behaege, T.J., 1974. Experiments on the seasonal variation of grass growth. Proc 12th Int Grassl Congr Moscow, 268–281.