6Johansson ME, Nilsson C (1993). Hydrochory, population dy- namics and distribution of the clonal aquatic plant Ranun- culus lingua. Journal of Ecology, 81, 81-91.
9Stromberg J, Gengarelly L, Rogers B (1997). Exotic herba- ceous species in Arizona's riparian ecosystems. In: Brock JH, Wade M, Pysek P, Green D eds. Plant Invasions: Studies from North America and Europe. Backhuys Pub- lishers, Leiden. 45-57.