Παραπομπή APA

Paul, P., & Wise, W. S. (1971). Principles of gas extraction. Mills and Boon.

Παραπομπή Chicago Style

Paul, P.F.M, και W. S. Wise. Principles of Gas Extraction. London: Mills and Boon, 1971.

Παραπομπή MLA

Paul, P.F.M, και W. S. Wise. Principles of Gas Extraction. Mills and Boon, 1971.