APA (7th ed.) Citation

Cummings, J., Cummings, L., & Frederiksen, L. (2007). User Preferences in Reference Services: Virtual Reference and Academic Libraries.

Chicago Style (17th ed.) Citation

Cummings, Joel, Lara Cummings, and Linda Frederiksen. User Preferences in Reference Services: Virtual Reference and Academic Libraries. 2007.

MLA (9th ed.) Citation

Cummings, Joel, et al. User Preferences in Reference Services: Virtual Reference and Academic Libraries. 2007.