APA (7th ed.) Citation

Hart, H. L. A. (1961). The concept of law (2nd ed.). Oxford university press.

Chicago Style (17th ed.) Citation

Hart, H. L. A. The Concept of Law. 2nd ed. Oxford: Oxford university press, 1961.

MLA (9th ed.) Citation

Hart, H. L. A. The Concept of Law. 2nd ed. Oxford university press, 1961.