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Sun P, Unger JB, Guo Q, Gong J, Ma H, Palmer PH, Chou CP, Li Y, Sussman S, Ritt-Olson A, Xiao L, Johnson CA.Sun P, et al. Among authors: johnson ca.Nicotine Tob Res. 2007 Nov;9 Suppl 4:S599-609. doi: 10.1080/14622200701697653.Nicotine Tob Res. 2007.PMID: 18067035Clinical Trial.
Sun P, Johnson CA, Palmer P, Arpawong TE, Unger JB, Xie B, Rohrbach LA, Spruijt-Metz D, Sussman S.Sun P, et al. Among authors: johnson ca.Int J Environ Res Public Health. 2012 Mar;9(3):660-73. doi: 10.3390/ijerph9030660. Epub 2012 Feb 23.Int J Environ Res Public Health. 2012.PMID: 22690154Free PMC article.
Rohrbach LA, Howard-Pitney B, Unger JB, Dent CW, Howard KA, Cruz TB, Ribisl KM, Norman GJ, Fishbein H, Johnson CA.Rohrbach LA, et al. Among authors: johnson ca.Am J Public Health. 2002 Jun;92(6):975-83. doi: 10.2105/ajph.92.6.975.Am J Public Health. 2002.PMID: 12036792Free PMC article.
Shakib S, Mouttapa M, Johnson CA, Ritt-Olson A, Trinidad DR, Gallaher PE, Unger JB.Shakib S, et al. Among authors: johnson ca.J Adolesc Health. 2003 Aug;33(2):88-97. doi: 10.1016/s1054-139x(03)00140-x.J Adolesc Health. 2003.PMID: 12890600
Valente TW, Hoffman BR, Ritt-Olson A, Lichtman K, Johnson CA.Valente TW, et al. Among authors: johnson ca.Am J Public Health. 2003 Nov;93(11):1837-43. doi: 10.2105/ajph.93.11.1837.Am J Public Health. 2003.PMID: 14600050Free PMC article.Clinical Trial.
Chen X, Li G, Unger JB, Liu X, Johnson CA.Chen X, et al. Among authors: johnson ca.Am J Public Health. 2003 Dec;93(12):2099-104. doi: 10.2105/ajph.93.12.2099.Am J Public Health. 2003.PMID: 14652341Free PMC article.
Johnson CA, Unger JB, Ritt-Olson A, Palmer PH, Cen SY, Gallaher P, Chou CP.Johnson CA, et al.Prev Med. 2005 Jun;40(6):842-52. doi: 10.1016/j.ypmed.2004.09.032.Prev Med. 2005.PMID: 15850886