APA (7th ed.) Citation

Low, O. (1980). Certificate of proficiency English practice (1. publ.). Arnold.

Chicago Style (17th ed.) Citation

Low, Ona. Certificate of Proficiency English Practice. 1. publ. London: Arnold, 1980.

MLA (9th ed.) Citation

Low, Ona. Certificate of Proficiency English Practice. 1. publ. Arnold, 1980.

Warning: These citations may not always be 100% accurate.