Naturally occurring retirement communities : a model for aging in place : hearing before the Subcommittee on Retirement Security and Aging of the Committee on Health, Education, Labor, and Pensions, United States Senate, One Hundred Ninth Congress, second session, on examining naturally occurring retirement communities and what impact they may have on the ability to create livable community options for all Americans, May 16, 2006. (U.S. G.P.O., 2006)