BibliographyStein, Mille, "Edvard Munch's paintings with bird droppings. Analysis of the Ekely collection at the Munch Museum", Zeitschrift für Kunsttechnologie und Konservierung, Jhrg. 25, Hft. 1, 2011, s. 93–101
Nielsen, Trine Otte Bak, Edvard Munch – De tre livsaldre 1907–1908, Oslo 2006, upubl. avhandling (Hovedoppgave), s. 29f