DUCK, C. D.; THOMPSON, D. The status of grey seals in Britain. NAMMCO Scientific Publications, [S. l.], v. 6, p. 69–78, 2013. DOI: 10.7557/3.2723. Disponível em: https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2723. Acesso em: 3 apr. 2025.