Encyclopedia of psychotherapy; Volume 2
edited by Michel Hersen, William Sledge
Academic Press, 2002
 Buku Referensi
Encyclopedia of knowledge : volume 1
Grolier Incorporated, 1991
 Buku Referensi
Encyclopedia of sociology; Volume 1
Edgar F. Borgatta, editor-in-chief, Marie L. Borgatta, managing editor
Macmillan, 1992
 Buku Referensi
Encyclopedia of television : volume 1
edited by Horace Newcomb
Fitzroy Dearborn Publishers, 1997
 Buku Referensi
Encyclopedia of linguistics : volume 1
Philipp Strazny, editor
Fitzroy Dearborn, 2005
 Buku Referensi