American Journal of Epidemiology (Vol. 176, No. 4, Aug. 15, 2012).
aje.oxfordjournals.org/content/176/4.toc?etoc
Archives of Gerontology and Geriatrics (Vol. 55, No. 2, September/October 2012).
www.sciencedirect.com/science/journal/01674943
Journal of the American Geriatrics Society (Vol. 60, No. 8, August 2012).
onlinelibrary.wiley.com/doi/10.1111/jgs.2012.60.issue-8/issuetoc