Cita APA (7a ed.)

Roberts, M. L., & Berger, P. D. (1989). Direct marketing management. Prentice Hall.

Cita Chicago Style (17a ed.)

Roberts, Mary Lou, y Paul D. Berger. Direct Marketing Management. Englewood Cliffs, N.J.: Prentice Hall, 1989.

Cita MLA (9a ed.)

Roberts, Mary Lou, y Paul D. Berger. Direct Marketing Management. Prentice Hall, 1989.