1. Breese, E.L. & E.J. Lewis, 1984. Breeding versatile hybrid grasses. Span. 27: 3–5.
2. Breese, E.L., E.J. Lewis & G.M. Evans, 1981. Interspecies hybrids and polyploidy. Philos. Trans. R. Soc. London Ser. B 299: 487–498.
3. Essad, S. 1964. Etude comparative des hybrides reciproques Lolium perenne L. x Festuca pratensis Huds. et de leur descendre. Ann. Amelior. Plantes 14(3): 295–308.
4. Gadish, I. & D. Zamir, 1987. Differential zygotic abortion in an interspecific Lycopersicon cross. Genome 29: 156–159.
5. Hayward, M.D. & N.J. McAdam. 1977. Isozyme polymorphism as a measure of distinctiveness and stability in cultivars of Lolium perenne. Z. Pflanzenzücht. 79: 59–68.