1. Developments in Hydrobiology;K. E. Granberg,1992
2. Hakkari, L. & P. Bagge, 1987. Reproductive success of Coregonus albula L. in polluted and unpolluted areas of L. P�ij�nne during the years 1977?1986. Biol. Res. Rep. Univ. Jyv�skyl� 10: 149?156.
3. Hakkari, L. & S. Bibiceanu, 1985. Siian, harjuksen ja muikun lis��ntymisbiologiasta vuosina 1980?83. In Saimaan ekologinen tutkimus vuosina, 1980?1983. Vesihallitus. Tiedotus 255: 187?206 (in Finnish).
4. Huusko, A., T. Sutela, J. Karjalainen, S. Hellsten & A. Hirvonen, 1989. Ecological aspects of lake regulation in northern Finland. Part 4. Spawning and the survival of the young fish. Techn. Res. Centre of Finland. Res. Notes 988: 1?95.
5. J�rvi, T. H., 1953. Uber die Coregonen s. str. im P�ij�nne und einigen anderen Gew�ssern Mittelfinnlands. Acta zool fenn 75: 1?33.