APA (7th ed.) Citation

Crystal, D., & Davy, D. (1975). Advanced conversational english. Longman Group.

Chicago Style (17th ed.) Citation

Crystal, David, and Derek Davy. Advanced Conversational English. Londres: Longman Group, 1975.

MLA (9th ed.) Citation

Crystal, David, and Derek Davy. Advanced Conversational English. Longman Group, 1975.