Hatch, John, author
Frederick A. Praeger, 1965
Buku Teks
Fage, J.D., author
Routledge, 1995
Buku Teks
Oliver, Roland
Penguin Books , 1966
Buku Teks
Eto, Jun
International Society for Educationa Information, 1974
Buku Teks
Padgett, Stephen
Longman, 1991
Buku Teks