Milton Friend, editor, Cynthia J. Laitman, technical editor ; Randy Stothard Kampen, illustrator (National Wildlife Health Center)U.S. Dept. of the Interior, Fish and Wildlife Service1987
compiled by Committee on Rare and Endangered Wildlife Species, Bureau of Sport Fisheries and Wildlife, U.S. Department of the InteriorFor sale by the Supt. of Docs., U.S. Govt. Print. Off.1968