1. Aldrich, D.T.A. 1987. Developments and procedures in the assessment of grass varieties at NIAB 1950–1987. J. Nat. Inst. Agric. Bot. 17:313–327.
2. Camlin, M.S. 1997. Plant breeding – achievements and prospects – grasses. In: J.R. Weddell (ed.) Seeds of progress, British Grassland Society Occasional Publication.
3. Camlin, M.S., Watson, S., Waters, B.G. and Weatherup, S.T.C. 2001. The potential for management of reference collections in herbage variety registration trials using a cyclic planting system for reference varieties. Plant Var. Seeds 14:1–14.
4. Culleton, N. and Cullen, T. 1992. Trends in herbage seed use in Ireland. Plant Var. Seeds 5:63–69.
5. Darwin, C. 1859. On the origin of species by means of natural selection (1st ed.). Murray, London.