SIPILÄ, T.; HYVÄRINEN, H. Status and biology of Saimaa (<i>Phoca hispida saimensis</i>) and Ladoga (<i>Phoca hispida ladogensis</i>) ringed seals. NAMMCO Scientific Publications, [S. l.], v. 1, p. 83–99, 1998. DOI: 10.7557/3.2982. Disponível em: https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2982. Acesso em: 12 aug. 2022.