Encyclopedia of mathematics Vol. 4
Kluwer Academic,
 Buku Referensi
Companion encyclopedia of psychology; Vol 1
edited by, Andrew M. Colman
Routledge, 1994
 Buku Referensi
Companion encyclopedia of psychology; Vol. 2
edited by Andrew M. Colman
Routledge, 1994
 Buku Referensi
The Encyclopedia of higher education vol. 4
Burton R. Clark, Guy R. Neave, editors-in-chief
Pergamon Press, 1992
 Buku Referensi
Encyclopedia of library and information science : vol. 4
Marcell Dekker, 1968
 Buku Referensi