Cummings, J., Cummings, L., & Frederiksen, L. (2007). User Preferences in Reference Services: Virtual Reference and Academic Libraries.
Citazione stile Chigago Style (17a edizione)Cummings, Joel, Lara Cummings, e Linda Frederiksen. User Preferences in Reference Services: Virtual Reference and Academic Libraries. 2007.
Citatione MLA (9a ed.)Cummings, Joel, et al. User Preferences in Reference Services: Virtual Reference and Academic Libraries. 2007.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.