Cita APA (7th ed.)

O'Hair, D., & Friedrich, G. W. (1997). Competent communication (2nd ed.). St. Martin's.

Cita Chicago (17th ed.)

O'Hair, Dan, i Gustav W. Friedrich. Competent Communication. 2nd ed. New York: St. Martin's, 1997.

Cita MLA (9th ed.)

O'Hair, Dan, i Gustav W. Friedrich. Competent Communication. 2nd ed. St. Martin's, 1997.