Artikel Jurnal
Boggs, Joseph M., author
Mountain View, Ca. Mayfield Publishing 1995,
Buku Teks
J.B. Kristanto, author
Kompas, 2004
Buku Teks
Rudy Windarmin Kasjmir, author
2007
UI - Skripsi (Membership)
Universitas Indonesia, 2006
UI - Skripsi (Membership)