APA

Evans V., Dooley J. & Blum E. (20). Environmental Science. Newbury: Express Publishing.

Chicago

Evans V, Dooley J and Blum E. 20. Environmental Science. Newbury: Express Publishing.

Harvard

Evans V., Dooley J. and Blum E. (20). Environmental Science. Newbury: Express Publishing.

MLA

Evans V, Dooley J and Blum E. Environmental Science. Newbury: Express Publishing. 20.