References
- Golterman, H. L., Clymo, R. S. & Ohnstad, M. A. M., 1978: Methods for Physical and Chemical Analysis of Fresh Waters — IBP Handbook 8, Blackwell Scientific Publ. Oxford, 213 pp.
- Mackareth, F. S. H., Heron, J. & Talling, J. F., 1978: Water Analysis. Some Revised Methods for Limnologists. — F. B. A. Scientific Publication 36, Ambleside, 117 pp.