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, , Growth and Sexual Dimorphism in the Skull of the Capercaillie Tetrao urogallus: A Multivariate Study of Geographical Variation, Ornis Scandinavica (Scandinavian Journal of Ornithology), Vol. 17, No. 2 (May, 1986), pp. 85-98
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Lindén et al. (1986) studied this question.
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