APA (7th ed.) Citation

O'Neill, G. K. (1981). 2081: A hopeful view of the human future. Simon and Schuster.

Chicago Style (17th ed.) Citation

O'Neill, Gerard K. 2081: A Hopeful View of the Human Future. New York: Simon and Schuster, 1981.

MLA (9th ed.) Citation

O'Neill, Gerard K. 2081: A Hopeful View of the Human Future. Simon and Schuster, 1981.