Cita APA (7a ed.)

Hanna, P. R., Kohn, C. F., & Steeg, C. L. V. (1971). Geography: Modular learning unit (United States studies.). Scott, Foresman.

Cita Chicago Style (17a ed.)

Hanna, Paul R., Clyde F. Kohn, y Clarence L. Ver Steeg. Geography: Modular Learning Unit. United States studies. Glenview, Ill: Scott, Foresman, 1971.

Cita MLA (9a ed.)

Hanna, Paul R., et al. Geography: Modular Learning Unit. United States studies. Scott, Foresman, 1971.