APA استشهاد

Bopp, R. E., & Smith, L. C. (2001). Reference and information services: An Introduction (3rd ed.). Libraries Unlimited.

استشهاد بنمط شيكاغو

Bopp, Richard E., و Linda C. Smith. Reference and Information Services: An Introduction. 3rd ed. Englewood, Colorado: Libraries Unlimited, 2001.

MLA استشهاد

Bopp, Richard E., و Linda C. Smith. Reference and Information Services: An Introduction. 3rd ed. Libraries Unlimited, 2001.