Руденко, А. Г. “Survey of Lesser Black-Backed Gull (Larus Fuscus Linnaeus, 1758) Migration and Wintering in the Azov-Black Sea Region”. The Journal of V.N.Karazin Kharkiv National University. Series «Biology», Vol. 25, 1, pp. 206-15, https://periodicals.karazin.ua/biology/article/view/5674.