Cusack K, Jonas DE, Forneris CA, Wines C, Sonis J, Middleton JC, Feltner C, Brownley KA, Olmsted KR, Greenblatt A, Weil A, Gaynes BN. Psychological treatments for adults with posttraumatic stress disorder: a systematic review and meta-analysis. Clin Psychol Rev. 2016 Feb;43:128-41. doi: 10.1016/j.cpr.2015.10.003
Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA. Incidence of IBS in a cohort of people with asthma. Dig Dis Sci. 2007 Feb 28;52(2):329-35.
Parsley (Edwards) TL. Review of the phantom respondents: opinion surveys and political representation. J Off Stat. 1994;10(3):351-5.