Shimada, Tetsuo, et al. “Frequency of Kleptoparasitism by Black Brant Branta Bernicla Nigricans on Eurasian Coot Fulica Atra Differs Between Years and Habitats”. Wildfowl, Nov. 2020, pp. 94-106, https://tidsskrift.dk/Wildfowl/article/view/154569.