APA (7th ed.) Citation

Michael Harris. (2006). Challenges Students Book ("?".). Pearson Education Limited.

Chicago Style (17th ed.) Citation

Michael Harris. Challenges Students Book. "?". England: Pearson Education Limited, 2006.

MLA (9th ed.) Citation

Michael Harris. Challenges Students Book. "?". Pearson Education Limited, 2006.

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