MLA

Neill, Alexander Sutherland. Summerhill. 2nd ed. Harmondsworth: Penguin books, 1972.

APA

Neill, A. Sutherland. (1972). Summerhill. 2nd ed. Harmondsworth: Penguin books.

Chicago

Neill, Alexander Sutherland, Summerhill. 2nd ed. Harmondsworth: Penguin books, 1972.