Sparks, John. Owls; their natural and unnatural history [by] John Sparks and Tony Soper. Illustrated by Robert Gillmor. - New York, Taplinger Pub. Co. [1970] - 206 p. illus. 22 cm. Bibliography: p. [198]-201. ISBN: 0800861701 Subjects--Topical Terms: Owls. LC Class. No.: QL696.S8 / S67 Dewey Class. No.: 598.9/7