CARLSSON, H.; CARLSSON, L.; WALLIN, C.; WALLIN, N.-E. Great Tits incubating empty nest cups. Ornis Svecica, Lund, Sweden, v. 1, n. 1, p. 51–53, 1991. DOI: 10.34080/os.v1.23096. Disponível em: https://journals.lub.lu.se/os/article/view/23096. Acesso em: 29 jan. 2023.