NILSSON, L. Changes in numbers and distribution of wintering waterfowl in Sweden during forty years, 1967–2006. Ornis Svecica, Lund, Sweden, v. 18, n. 3–4, p. 135–226, 2008. DOI: 10.34080/os.v18.21852. Disponível em: https://journals.lub.lu.se/os/article/view/21852. Acesso em: 16 oct. 2021.