Cita APA (7th ed.)

GIBSON, J. (1990). SUPERVISORY CHALLENGES. MERRILL PUB. CO.

Cita Chicago (17th ed.)

GIBSON, J.W. SUPERVISORY CHALLENGES. COLUMBUS: MERRILL PUB. CO, 1990.

Cita MLA (9th ed.)

GIBSON, J.W. SUPERVISORY CHALLENGES. MERRILL PUB. CO, 1990.