APA (7th ed.) Citation

Leech, G. N., Cruickshank, B., & Ivanič, R. (1991). An A-Z of English grammar and usage. Nelson.

Chicago Style (17th ed.) Citation

Leech, Geoffrey N., Benita Cruickshank, and Roz Ivanič. An A-Z of English Grammar and Usage. Edinburgh: Nelson, 1991.

MLA (9th ed.) Citation

Leech, Geoffrey N., et al. An A-Z of English Grammar and Usage. Nelson, 1991.