APA (7th ed.) Citation

Wheeler, W. M., & Parker, G. H. (1939). Essays in philosophical biology. Harvard University Press.

Chicago Style (17th ed.) Citation

Wheeler, William Morton, and George Howard Parker. Essays in Philosophical Biology. Cambridge: Harvard University Press, 1939.

MLA (9th ed.) Citation

Wheeler, William Morton, and George Howard Parker. Essays in Philosophical Biology. Harvard University Press, 1939.