APA (7th ed.) Citation

O'Neill, R. V. (1986). A Hierarchical concept of ecosystems. Princeton University Press.

Chicago Style (17th ed.) Citation

O'Neill, R. V. A Hierarchical Concept of Ecosystems. Princeton, N.J.: Princeton University Press, 1986.

MLA (9th ed.) Citation

O'Neill, R. V. A Hierarchical Concept of Ecosystems. Princeton University Press, 1986.