APA (7th ed.) Citation

Derbyshire, J. D., & Derbyshire, I. (1989). Political systems of the world. Chambers.

Chicago Style (17th ed.) Citation

Derbyshire, J. Dennis, and Ian Derbyshire. Political Systems of the World. Edinburgh: Chambers, 1989.

MLA (9th ed.) Citation

Derbyshire, J. Dennis, and Ian Derbyshire. Political Systems of the World. Chambers, 1989.