Dale, Margaret
Gramedia, 2003
Buku Teks
Billsberry, Jon.
John Wiley & Sons, 2007
Buku Teks
The British Council and the Publisher Association, 1992
Buku Referensi
Bowey, Angela
Macmillan, 1974
Buku Teks
Eko Pramono
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2001
UI - Tesis (Membership)