APA استشهاد

Spencer, E. W. (1962). Basic concepts of historical geology. Oxford & IBH.

استشهاد بنمط شيكاغو

Spencer, Edgar Winston. Basic Concepts of Historical Geology. New Delhi: Oxford & IBH, 1962.

MLA استشهاد

Spencer, Edgar Winston. Basic Concepts of Historical Geology. Oxford & IBH, 1962.