APA استشهاد

Smith, P. M., & Warr, K. E. (1991). Global environmental issues.

استشهاد بنمط شيكاغو

Smith, Paul M., و Kiki; Ed Warr. Global Environmental Issues. London, Hodder & Stoughton, 1991.

MLA استشهاد

Smith, Paul M., و Kiki; Ed Warr. Global Environmental Issues. 1991.