Arana A, Cuchi T, Arellano F. Strengthening EU pharmacovigilance. European pharmaceutical contractor. European pharmaceutical contracto: EPC. 2009;44-5.
Britt (DiBenedetti) DM, Collins FL, Cohen LM. Cigarette smoking and chewing gum use among college students. J Appl Biobehav Res. 2007 Jun 4;4(2):85-90. doi: 10.1111/j.1751-9861.1999.tb00057.x
Dysktra LA, Granger AL. Interactions between the delta agonist SNC80, and the mu agonists, morphine, buprenorphine, and butorphanol in squirrel monkeys. Nida Res Monogr. 2000;180:65.
Gfroerer J, Lessler J, Parsley (Edwards) T. Studies of nonresponse and measurement error in the national household survey on drug abuse. Nida Res Monogr. 1997;167:273-95.