Witters, H.E.; Van Puymbroeck, S.; Berckmans, P. (1994). Global change and freshwater ecosystems, in: Vanderborght, O. et al. (Ed.) IGBP and 'Global Change' related research in Belgium II. pp. 86
In: Vanderborght, O.; Janssens, E. (Ed.) (1994). IGBP and 'Global Change' related research in Belgium II. Royal Belgian Academy of Sciences: Brussel. ISBN 90-6569-609-1. 259 pp., more