Ratih Andrini, author
Universitas Indonesia, 2014
UI - Skripsi (Membership)
Chandler, Cristine
McGraw-Hill, 2004
Buku Teks
Rainey, Dennis, author
Arkansas: The Lockman Foundation; 1989,
Buku Referensi
Fisher, Bruce, author
Grasindo, 2003
Buku Teks
Lawrence, Anne
Minerve Press, 1996
Buku Teks