1. Botnariuc, N., Vadineanu A. (1982) Ecology, Didactic and Pedagogical Publisher, Bucharest.
2. Diaconu, C. (1971) The Romanian River, Didactic and Pedagogical Publisher, Bucharest.
3. Puia, I., Soran, V. (1988) Stability, Diversity, Vulnerability, Didactic and Pedagogical Publisher, Bucharest.
4. Pirvu, C. (1980) Romanian Ecosystems, Ceres Publisher.
5. Stugren, B., (1982) Modern Ecology Problem, Scientific and Encyclopedic Publisher, Bucharest.