Artikel Jurnal
Agung Erwan Setyobudi
Universitas Indonesia, 2007
UI - Tesis (Membership)
Gaudin, A.M.
Tata McGraw-Hill, 1978
Buku Teks
Lumbanraja, Yannet Natoho
2005
UI - Tesis (Membership)
Richards, Robert H.
McGraw-Hill Book Company, Inc., 1940
Buku Teks