References
- Barica, J., 1989 a: Increases of nitrate in the Great Lakes. — Proceeding of the 5th Intern. Symposium of CIEC: 61–67. CIEC Göttingen.
- Barica, J. 1989 b: Recovery of the Laurentian Great Lakes, 1970–1985: Eutrophication aspects. — Proceedings of the ILEC Conference “Balaton 88”: 43–59.
- International Joint Commission (IJC), 1987: 1987 Report on Great Lakes Water Quality. — Great Lakes Water Quality Board, Toledo, Ohio, 236 pp.