Gotlib, Ian H., Eva Gilboa, and Beth Kaplan Sommerfeld. "Cognitive Functioning in Depression: Nature and Origins." Anxiety, Depression, and Emotion. : Oxford University Press, 2000-08-24. Oxford Scholarship Online. 2012-03-22. Date Accessed 26 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195133585.001.0001/acprof-9780195133585-chapter-7>.
Gotlib, I., Gilboa, E., & Sommerfeld, B.(2000-08-24). Cognitive Functioning in Depression: Nature and Origins. In Anxiety, Depression, and Emotion. : Oxford University Press. Retrieved 26 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195133585.001.0001/acprof-9780195133585-chapter-7.
Gotlib, Ian H., Eva Gilboa, and Beth Kaplan Sommerfeld. "Cognitive Functioning in Depression: Nature and Origins." In Anxiety, Depression, and Emotion. : Oxford University Press, 2000-08-24. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195133585.001.0001/acprof-9780195133585-chapter-7.
Gotlib IH, Gilboa E, Sommerfeld BK. Cognitive Functioning in Depression: Nature and Origins. In: Davidson RJ. Anxiety, Depression, and Emotion. Oxford University Press; 2000. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195133585.001.0001/acprof-9780195133585-chapter-7. Accessed May 26, 2013.