References
- Adams, F. S., Mackensie D. R., Cole, H. Jr., & Price, M. W., 1971: The influence of nutrient pollution levels upon element constitution and morphology of Elodea canadensis Rich, in Michx. — Environ. Poll. 1: 285–298.
- Gerloff, G. C., 1975: Nutritional ecology of nuisance aquatic plants. — U. S. Environm. Protection Agency Res. Ser., 660/3-75-027, 78 p.
- Gerloff, G. C. & Fishbeck, K. A., 1973: Plant content of elements as a bioassay of nutrient availability in lakes and streams. — In: Bioassay Tech. and Envir. Chem: 159— 176. Ann Arbor Science Publishers, Inc.
- Jackson, M. L., 1958: Soil Chemical Analysis. — Prentice-Hall Englewood Cliffs, New Jersey, 498 pp.
- Keup, L. E., 1968: Phosphorus in flowing waters. — Water Res. 2: 373–386.
- Mccoll, R. H. S., 1974: Self-purification of small freshwater streams: Phosphate, nitrate, and ammonia removal. — N. Z. J. Marine Freshwater Res. 8: 375–388.
- Mehta, N. C., Legg, J. O., Goring, G. A. I. & Black, C. A., 1954: Determination of organic phosphorus in soils. I. Extraction Method. — Soil Sci. Sci. Amer. Proc. 18: 443–449.
- Menzel, D. W. & Corwin, N., 1965: The measurement of total phosphorus in seawater based on the liberation of organically bound fractions by persulfate oxidation. — Limnol. Oceanogr. 10: 280–282.
- Sommers, L. E., Harris, R. F., Williams, J. D. H., Armstrong, D. E. & Syers, J. K., 1970: Determination of total organic phosphorus in lake sediments. — Limnol. Oceanogr. 15: 301–303.
- Stake, E., 1968: Higher vegetation and phosphorus in a small stream in Central Sweden. — Schweiz. Z. Hydrol. 30: 353–373.
- Stein, R. A., Mecom, J. O. & IvanoviĆ, B., 1975: Commercial exploitation of fish stocks in Skadar Lake, Yugoslavia 1947— 1973. — Biol. Conserv. 8: 1–18.
- Strickland, J. D. H. & Parsons, T. R., 1972: A practical handbook of seawater analysis. — Fish. Res. Board Canada, Bull. 167: 310 p. 2nd ed., Ottawa.
- Wong, S. L. & Clark, B., 1976: Field determination of the critical nutrient concentrations for Cladophora in streams. — J. Fish. Res. Board Can. 33: 85–92.