Cita APA (7a ed.)

Armstrong, D. M. (1993). What is a law of nature? (1st pbk. ed.). University Press.

Cita Chicago Style (17a ed.)

Armstrong, D. M. What Is a Law of Nature? 1st pbk. ed. Cambridge: University Press, 1993.

Cita MLA (9a ed.)

Armstrong, D. M. What Is a Law of Nature? 1st pbk. ed. University Press, 1993.