Franson, J. C., T. Hollmén, R. H. Poppenga, M. Hario, och M. Kilpi. 2000. ”Metals and Trace Elements in Tissues of Common Eiders (Somateria Mollissima) from the Finnish Archipelago”. Ornis Fennica 77 (2):57–63. https://ornisfennica.journal.fi/article/view/133526.