Park EM, Deal AM, Yopp JM, Edwards TP, Wilson DJ, Hanson LC, Rosenstein DL. End-of-life experiences of mothers with advanced cancer: perspectives of widowed fathers. BMJ Support Palliat Care. 2016 Dec;6(4):437-44. doi: 10.1136/bmjspcare-2015-000976
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