Kilpi, M. “Responses of Herring Gulls Larus Argentatus and Common Gulls L. Canus to Warm Years: Early Migration and Early Breeding”. Ornis Fennica 69, no. 2 (July 1, 1992): 82–87. Accessed November 22, 2024. https://ornisfennica.journal.fi/article/view/133342.