Verevkin, Mikhail, Vadim Vysotsky, and Rustam Sagitov. “Aerial Survey of Baltic Ringed Seals (<em>Pusa Hispida botnica< Em>) in the Russian Part of the Gulf of Finland”. Biological Communications, no. 1 (March 5, 2012): 38–46. Accessed April 25, 2024. https://biocomm.spbu.ru/article/view/4801.