Gaya APA

Swanson, C, P., Stidworthy, J. (NULL). Encyclopedia of science plants and animals 5 . New: New York: Macmillan; 1991.

Gaya MLA

Swanson, Carl, P.., Stidworthy, John. "Encyclopedia of science plants and animals 5". New: New York: Macmillan; 1991, NULL. Text.