Barker, D.W.
Exercises in good English book 3 / D. W. Barker
Macmillan and Co., 1953
 Buku Teks
Drummond, Gordon
English sentence patterns and multi-level practice exercises with grammar notes
Essex Longman, 1972
 Buku Teks
Hewings, Martin
Pronunciation practice activities : a resource book for teaching english pronunciation
Cambridge University Press , 2004
 Buku Teks SO
Dowling, Barbara Tolley
Business concepts for English practice
Newbury House Publishers , 1982
 Buku Teks
Close, R.A.
English we use anthology of current usage with exercises for practice in the spoken and written language / Close R.A.
Longmans , 1967
 Buku Teks