Barnes, A. James, author
Learning Systems, 1981
Buku Teks
Pritchard, John, author
Viking, 1992
Buku Referensi
Carvan, John, author
LBC Information Services, 1997
Buku Teks
Bainbridge, David I., author
Pitman , 1993
Buku Teks
edited by Richard Haigh, Dai Harris
Routledge, 1994
Buku Teks