APA (7th ed.) Citation

Leech, J. W., & Newman, D. J. (1969). How to use groups. Methuen.

Chicago Style (17th ed.) Citation

Leech, J. W., and D. J. Newman. How to Use Groups. London: Methuen, 1969.

MLA (9th ed.) Citation

Leech, J. W., and D. J. Newman. How to Use Groups. Methuen, 1969.