1. Allen, G. O. 1950. British Stoneworts (Charophyta). Haslemere Natural History Society 52 pp.
2. Backman, A. L. 1948. Najas flexilis in Europa w�hrend der Quartarzeit. Acta Bot. Fenn. 43: 1?44.
3. Braun-Blanquet, J. & T�xen, R. 1952. Irische Pflanzengesell-schaften. Ver�ff. Geobot. Inst. R�bel in Z�rich 25: 224?415.
4. Caffrey, J. M. & Rorslett, B. 1989. The macrophytic vegetation in Rusheenduff (Renvyle) Lough, Co. Galway. Ir. Nat. J. 23: 125?128.
5. Champ, W. S. T. 1977. Trophic status of fishery lakes. In: Lake Pollution Eutrophication Control ed. Downey and Ni, Uid, 65?78. Stationery Office, Dublin 1977.