Encyclopedia of marriage and the family : volume 1
David Levinson, editor in chief
Simon & Schuster Macmillan, 1995
 Buku Referensi
Encyclopedia of social psychology : 2
Roy F. Baumeister, Kathleen D. Vohs, editors
Sage Publications, 2007
 Buku Referensi
The Encyclopedia Americana : volume 2
Americana Corporation, 1977
 Buku Referensi
The Encyclopedia Americana : volume 2
Americana Corporation, 1964
 Buku Referensi
Encyclopedia of linguistics : volume 2
Philipp Strazny, editor
Fitzroy Dearborn, 2005
 Buku Referensi