• [Wiki] http://en.wikipedia.org/wiki/Tetrao_urogallus.
• [AnAge] http://genomics.senescence.info/species/entry.php?species=Tetrao_urogallus.
• [avibase] https://avibase.bsc-eoc.org/species.jsp?lang=EN&avibaseid=C3221EE24B948F50&sec=lifehistory.
• [ADW] https://animaldiversity.org/accounts/Tetrao_urogallus/.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.
• [MiloLind1989] Milonoff, M. and Lindén, H. (1989). Sexual size dimorphism of body components in capercaillie chicks. Ornis Scandinavica (Scandinavian Journal of Ornithology), 20(1):29--35.
• [PrinPres1991] Prinzinger, R., A.Preßmar, and Schleucher, E. (1991). Body temperature in birds. Comp. Biochem. Physiol., 99A(4):499--506. doi:10.1016/0300-9629(91)90122-S.