Mann, Richard, author
Gateway Books, 2000
Buku Teks
Eto, Jun
International Society for Educationa Information, 1974
Buku Teks
A.M. Hendropriyono, author
Hendropriyono Strategic Consulting, 2020
Buku Teks SO
Gavin, Angus, author
Academy Editions, 1996
Buku Teks
Lee, Martyn J.
Routledge, 1993
Buku Teks