APA Edition Citation

Derbyshire, I., & Derbyshire, J. D. (1990). Political systems of the world.

Chicago Edition Citation

Derbyshire, Ian, and J Denis Derbyshire. Political Systems of the World. New Delhi, Allied Publishers, 1990.

MLA Edition Citation

Derbyshire, Ian, and J Denis Derbyshire. Political Systems of the World. 1990.