APA (7th ed.) Citation

Ellwood, W., Guerin, P., Purser, P., & Rush, N. (1991). It's a mathematical world. 2. Longman paul Limited.

Chicago Style (17th ed.) Citation

Ellwood, W., P. Guerin, P. Purser, and N. Rush. It's a Mathematical World. 2. Auckland: Longman paul Limited, 1991.

MLA (9th ed.) Citation

Ellwood, W., et al. It's a Mathematical World. 2. Longman paul Limited, 1991.