Underhill, Kristen, Kathleen M. Morrow, Christopher Colleran, Sarah K. Calabrese, Don Operario, Peter Salovey, and Kenneth H. Mayer. "Explaining the Efficacy of Pre-exposure Prophylaxis (PrEP) for HIV Prevention: A Qualitative Study of Message Framing and Messaging Preferences Among US Men Who have Sex with Men." AIDS and behavior (2015).