LeFever, M. D. (1973). Turnabout teaching. Cook Publishing.
Cita Chicago (17th ed.)LeFever, Marlene D. Turnabout Teaching. Cook Publishing, 1973.
Cita MLA (9th ed.)LeFever, Marlene D. Turnabout Teaching. Cook Publishing, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.