Cita APA (7a ed.)

Armstrong, D. M. (1983). Whats is a law of nature. Cambridge University Press.

Cita Chicago Style (17a ed.)

Armstrong, D. M. Whats Is a Law of Nature. Cambridge: Cambridge University Press, 1983.

Cita MLA (9a ed.)

Armstrong, D. M. Whats Is a Law of Nature. Cambridge University Press, 1983.