Niaura R, Britt DM, Shadel WG, Goldstein M, Abrams D, Brown R. Symptoms of depression and survival experience among three samples of smokers trying to quit. Psychol Addict Behav. 2001 Mar 1;15(1):13-7.
Knox D, Gibson L, Zusman ME, Gallmeier C. Why college students end relationships. Coll Stud J. 1997 Jan 1;31(4):449-52.