Mechanisms explaining a pay-it-forward approach: A qualitative analysis among men who have sex with men in China oleh Margaret Byrne, Rayner Kay Jin Tan, Dorian Ho, Gifty Marley, Rohit Ramaswamy, Katherine Li, Tong Wang, Rong Mu, Qiwen Tang, Qilei Sheng, Dan Wu, Weiming Tang, Sean S. Sylvia, Dong Roman Xu, Cheng Wang, Joseph D. Tucker