Fischer A, Zimovetz E, Ling C, Esser D, Shoof N. Humanistic and cost burden of systemic sclerosis: a review of the literature. Autoimmun Rev. 2017 Nov;16(11):1147-54. doi: 10.1016/j.autrev.2017.09.010
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