Petersen, Æ., Petersen, A., & Perrins, C. (1981). Breeding biology and feeding ecology of Black guillemots.
Chicago-čujuhus (17. p.)Petersen, Æ, Aevar Petersen, juo C. Perrins. Breeding Biology and Feeding Ecology of Black Guillemots. 1981.
MLA-čujuhus (9. p.)Petersen, Æ, et al. Breeding Biology and Feeding Ecology of Black Guillemots. 1981.
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