Kilpi, M. “Offspring-Defence Behaviour towards a Human Intruder in Three Species of Gulls: Larus Marinus, L. Argentatus and L. Canus”. Ornis Fennica 65, no. 4 (December 31, 1988): 156–162. Accessed November 22, 2024. https://ornisfennica.journal.fi/article/view/133268.