APA (7th ed.) Citation

Harper Collins, Willis, D., & Wright, J. (1995). Collins Cobuild basic grammar: Helping learners with real English. Harper Collins.

Chicago Style (17th ed.) Citation

Harper Collins, Dave Willis, and Joh Wright. Collins Cobuild Basic Grammar: Helping Learners with Real English. London: Harper Collins, 1995.

MLA (8th ed.) Citation

Harper Collins, et al. Collins Cobuild Basic Grammar: Helping Learners with Real English. Harper Collins, 1995.