1. Ahlgren, I., 1967. Limnological studies of Lake Norrviken, a eutrophicated Swedish lake. I. Water chemistry and nutrient budget. Schweiz. Z. Hydrol. 29:53–90.
2. Ahlgren, G., 1970. Limnological studies of Lake Norrviken, a eutrophicated Swedish lake. II. Phytoplankton and its production. Ibid., 32:353–396.
3. Austin, E.R. & G.F. Lee, 1973. Nitrogen release from lake sediments. J. Wat. Pollut. Control Fed., 45:870–879.
4. Bengtsson, L., 1975. Phosphorus release from a highly eutrophic lake sediment Verh. Internat. Verein. Limnol. 19:1107–1116.
5. Björk, S., 1972. Swedish lake restoration program gets results. Ambio 1:153–165.