Jarvis, Matt, 1966-, author
Routledge, 2005
Buku Teks
Young, Kimball
Kegan Paul, Trench, Trubner, 1946
Buku Teks
Eysenck, Michael W., author
Psychology Press, 2005
Buku Teks
editor, James E. Birren and K. Warner Schaie
Academic Press, 1990
Buku Referensi
edited by Michael J. Stevens and Danny Wedding
Brunner-Routledge, 2004
Buku Teks