APA

Gaman W. A., Giovinazzo W. A., . (1991). PHIGS by example. New York: Springer.

Chicago

Gaman William A, Giovinazzo William A, . 1991. PHIGS by example. New York: Springer.

Harvard

Gaman W. A., Giovinazzo W. A., . (1991). PHIGS by example. New York: Springer.

MLA

Gaman William A, Giovinazzo William A, . PHIGS by example. New York: Springer. 1991.