WASENIUS, E. Ägg av Strix. a. aluco L, Strix u. uralensis Pall. och Strix nebulosa lapponica Thunb. Ornis Fennica, [S. l.], v. 6, n. 4, p. 114–115, 1929. Disponível em: https://ornisfennica.journal.fi/article/view/132240. Acesso em: 16 may. 2024.