APA (7th ed.) Citation

Ruf, J. A. (1973). Resource recovery in perspective. Chemical Engineering Progress, 69, 21.

Chicago Style (17th ed.) Citation

Ruf, J. A. "Resource Recovery in Perspective." Chemical Engineering Progress 69 (1973): 21.

MLA (9th ed.) Citation

Ruf, J. A. "Resource Recovery in Perspective." Chemical Engineering Progress, vol. 69, 1973, p. 21.

Warning: These citations may not always be 100% accurate.