Cita APA (7th ed.)

Smith Carl B. & Arnold, V. A. (1986). Opening doors. Macmillan Publishing.

Cita Chicago (17th ed.)

Smith Carl B. i Virginia A. Arnold. Opening Doors. New York: Macmillan Publishing, 1986.

Cita MLA (9th ed.)

Smith Carl B. i Virginia A. Arnold. Opening Doors. Macmillan Publishing, 1986.