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2. Daan, S. & J. Aschoff 1975. Circadian rhythms of locomotor activity in captive birds and mammals: Their variations with season and latitude. Oekologia 18: 269–316.
3. Eriksson, L.-O. 1973. Spring inversion of the diel rhythm of locomotor activity in young sea-going brown trout, Salmo trutta trutta L., and Atlantic salmon, Salmo salar L. Aquilo Ser. Zool. 14: 68–79.
4. Eriksson, L.-O. 1975. Diel and annual locomotor activity rhythms in some fresh water fish species with special referrence to the seasonal inversion in salmonids. Thesis, University of Ume», Ume», Sweden.
5. Eriksson, L.-O. & F. Kubicek 1972. An experimental study of the vertical migration in whitefish. Fauna och flora (Stockholm) 67: 224–228 (in Swedish).