Fassberg, M. M., van Orden, K. A., Duberstein, P., Erlangsen, A., Lapierre, S., Bodner, E., . . .Waern, M. (2012). A systematic review of social factors and suicidal behavior in older adulthood. International Journal of Environmental Research and Public Health, 9(3), 722-745. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3367273/