Clarke, Geoffrey M
American Elsevier Publishing, 1969
Buku Teks
Bartee, Edwin M., author
Prentice-Hall, 1968
Buku Teks
Nurul Lathifah, author
2017
UI - Skripsi (Membership)
Atkinson, A. C., author
Clarendon Press, 1992
Buku Teks
Kirk, Roger E, author
Sage Publications, 2013
Buku Teks