Hoffman, P. (1983). American Museum guides sciences. Macmillan.
Cita Chicago (17th ed.)Hoffman, Paul. American Museum Guides Sciences. Macmillan, 1983.
Cita MLA (9th ed.)Hoffman, Paul. American Museum Guides Sciences. Macmillan, 1983.
Atenció: Aquestes cites poden no estar 100% correctes.