1. Aminot, A. & Chaussepied, M: 1993, Manuel des analyses chimiques en milieu marin. CNEX, Paris.
2. Andersen, J.M.: 1976,Water Research 10, 329–331.
3. APHA (ed): 1989,Standard Methods for the Examination of Water and Wastewater. Washington.
4. Beboult, B.M.; Fitzpatrick, M.W. & Paerl H.W.: 1993,Appl. Envir. Microbial. 59, 1495–1503.
5. Casado, S. Florin, M. Mollá, S. and Mantes, C.: 1992,Managing Mediterranean Wetlands and their Birds, IWRB Special Publications No. 20. IWRB & Istituto Nazionale di Biologia della Selvaggina, 56–58.