Cita APA (7a ed.)

Bopp, R. E., & Smith, L. C. (2011). Reference and information services: An introduction (4th ed.). Libraries Unlimited.

Cita Chicago Style (17a ed.)

Bopp, Richard E., y Linda C. Smith. Reference and Information Services: An Introduction. 4th ed. Santa Barbara, Calif.: Libraries Unlimited, 2011.

Cita MLA (8a ed.)

Bopp, Richard E., y Linda C. Smith. Reference and Information Services: An Introduction. 4th ed. Libraries Unlimited, 2011.