WHITTINGTON, P.; KLAGES, N.; CRAWFORD, R.; WOLFAARDT, A.; KEMPER, J. Age at first breeding of the African Penguin. Ostrich: Journal of African Ornithology, [S. l.], v. 76, n. 1-2, p. 14–20, 2005. DOI: 10.2989/00306520509485468. Disponível em: https://www.ajol.info/index.php/ostrich/article/view/20164. Acesso em: 8 nov. 2026.