Maurrasse, David J., author
Routledge , 2001
Buku Teks
Yankelovich, Daniel
Washington Square Press, 1972
Buku Teks
Abimanyu, author
Fakultas Teknik Universitas Indonesia, 2001
UI - Skripsi (Membership)
Gurnsey, Lisa, author
Bremmer and Goris Communications, Inc, 2003
Buku Teks
Artikel Jurnal