Grajewska, Agnieszka, et al. “Evaluation of Claws As an Alternative Route of Mercury Elimination from the Herring Gull (Larus Argentatus)”. Oceanological and Hydrobiological Studies, vol. 48, no. 2, June 2019, pp. 165-73, https://czasopisma.bg.ug.edu.pl/index.php/oandhs/article/view/8014.