Gunawan Widjaja, author
Kencana Prenada Media Group, 2006
Buku Teks
Gunawan Widjaja, author
[s.n.], [s.a.]
Buku Teks
Gunawan Widjaja, author
Kencana Prenada Media Group, 2006
Buku Teks
Universitas Indonesia, 1998
UI - Skripsi (Membership)
Neng Djubaedah, author
Kencana Prenada Media, 2009
Buku Teks