APA (7th ed.) Citation

U.S. Fish and Wildlife Service. (1995). Walrus: Odobenus rosmarus. The Service.

Chicago Style (17th ed.) Citation

U.S. Fish and Wildlife Service. Walrus: Odobenus Rosmarus. [Washingon, D.C.?]: The Service, 1995.

MLA (9th ed.) Citation

U.S. Fish and Wildlife Service. Walrus: Odobenus Rosmarus. The Service, 1995.