International Association of Gerontology; edited by Clark Tibbitts and Wilma Donahue
Columbia University Press, 1962
Buku Teks SO
Jarvela, Sanna
Elsiever, 2011
Buku Teks
edited by Albert I. Wertheimer and Mickey C. Smith
University Park Press, 1981
Buku Teks
Larkin, Mary
McGraw-Hill, 2011
Buku Teks SO
Ward, John
Roche, 1980
Buku Teks SO