King RM, Vidrine DJ, Danysh HE, Fletcher FE, McCurdy S, Arduino RC, Gritz ER. Factors associated with nonadherence to antiretroviral therapy in HIV-positive smokers. AIDS Patient Care STDS. 2012 Aug;26(8):479-85. doi: 10.1089/apc.2012.0070
Fondell E, Lagerros YT, Sundberg CJ, Lekander M, Balter O, Rothman KJ, Balter K. Physical activity, stress, and self-reported upper respiratory tract infection. Med Sci Sports Exerc. 2011 Feb 1;43(2):272-9.