Dale, Margaret, author
Gramedia, 2003
Buku Teks
Condliffe, Peter, author
Lexis lexis, 2012
Buku Teks
Ewles, Linda, author
Scutari Press, 1995
Buku Referensi
Moss, Geoffrey, author
Gramedia, 1997
Buku Teks
Mercado, Cesar M., author
Development Consultant For Asia Pasific, 1999
Buku Teks