OTTVALL, R.; EDENIUS, L.; ELMBERG, J.; ENGSTRÖM, H.; GREEN, M.; HOLMQVIST, N.; LINDSTRÖM, Åke; PÄRT, T.; TJERNBERG, M. Population trends for Swedish breeding birds. Ornis Svecica, Lund, Sweden, v. 19, n. 3, p. 117–192, 2009. DOI: 10.34080/os.v19.22652. Disponível em: https://journals.lub.lu.se/os/article/view/22652. Acesso em: 17 may. 2022.