1. Alston, R. E., 1966: Chemotaxonomy or biochemical systematics? ? InSwain, T., (Ed.): Comparative phytochemistry, pp. 33?56. ? New York: Academic Press.
2. Arber, A., 1920: Water plants: a study of aquatic angiosperms. ? Cambridge: Cambridge University Press.
3. Cavalier-Smith, T., (Ed.) 1985: The evolution of genome size. ? New York: Wiley.
4. Clark, H. L., Thieret, J. W., 1968: The duckweeds of Minnesota. ? Michigan Bot.7: 67?76.
5. Cook, C. D. K., 1990: Aquatic plant book. ? The Hague, The Netherlands: SPB Academic Publishing.