Guttman, S. A. (1995). [D - F]. North Waterloo Academic Press.
Cita Chicago (17th ed.)Guttman, Samuel A. [D - F]. Waterloo, Ontario: North Waterloo Academic Press, 1995.
Cita MLA (8th ed.)Guttman, Samuel A. [D - F]. North Waterloo Academic Press, 1995.
Atenció: Aquestes cites poden no estar 100% correctes.