Callow, Duncan
Otter Publications , 1995
Buku Teks
Callow, Duncan
Chischester, 1995
Buku Teks
Benjamin, Jane, author
Fourmat Publishing, 1993
Buku Teks
Artikel Jurnal
Romin Thaib, author
Program Pascasarjana Universitas Indonesia, 2006
UI - Tesis (Membership)