Daniels, Rick
Delmar Cengage Learning, 2012
Buku Referensi
Daniel, Rick
Delmar, Cengage Learning, 2012
Multimedia
Daniel, Rick
Delmar, Cengage Learning, 2012
Multimedia
Peter Salim
Modern English Press, [date of publication not identified]
Buku Referensi
Jones, Gareth R.
McGraw-Hill, Irwin, 2006
Buku Teks