Παραπομπή APA

Northrop, J., & ...[et al.]. (1939). Crystalline enzymes/2nd ed (2nd ed.). Columbia unicersity.

Παραπομπή Chicago Style

Northrop, John, και ...[et al.]. Crystalline Enzymes/2nd Ed. 2nd ed. New york: Columbia unicersity, 1939.

Παραπομπή MLA

Northrop, John, και ...[et al.]. Crystalline Enzymes/2nd Ed. 2nd ed. Columbia unicersity, 1939.