1. Gilakjani A.P., Studies in Education. J. E, 1, (2011).
2. Clark J., Yallop C. and Fletcher J. An Introduction to Phonetics and Phonology 3rd ed, (Victoria, Blackwell, 2007)
3. Dobrovolsky M., & Higgins E.C. Phonology: The Function and Patterning of Sounds. In O’Grady, W., & Archibald, J., Contemporary Linguistics, (Boston, Bedford/St. Martin’s, 2001).
4. Fromkin V., Rodman R. and Hyams N. An Introduction to Language (8 th ed.), (Boston, MA, Thomson Wadsworth, 2007).
5. Kelly Gerald. How to Teach Pronunciation. Series Editor Jeremy Harmer, (Charlbury, Oxfordshire, UK, Bluestone Press, 2010).