COLLIER'S ENCYCLOPEDIA, HALSEY, W. D. [., & JOHNSTON, B. [. (1989). Collier's encyclopedia vol.4. Macmillan Educational.
Cita Chicago (17th ed.)COLLIER'S ENCYCLOPEDIA, William D. [Edt.] HALSEY, i Bernard [Edt.] JOHNSTON. Collier's Encyclopedia Vol.4. New York: Macmillan Educational, 1989.
Cita MLA (9th ed.)COLLIER'S ENCYCLOPEDIA, et al. Collier's Encyclopedia Vol.4. Macmillan Educational, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.