Thom, T. J. (1997). The relationship between the distribution of otter (Lutra lutra, L.) signs and habitat in the upper Tyne river catchment, NE England.
Chicago-referens (17:e uppl.)Thom, Timothy James. The Relationship Between the Distribution of Otter (Lutra Lutra, L.) Signs and Habitat in the Upper Tyne River Catchment, NE England. 1997.
MLA-referens (8:e uppl.)Thom, Timothy James. The Relationship Between the Distribution of Otter (Lutra Lutra, L.) Signs and Habitat in the Upper Tyne River Catchment, NE England. 1997.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.