Cita APA (7a ed.)

Armstrong, D. M. (1989). Universals: An opinionated introduction. Westview.

Cita Chicago Style (17a ed.)

Armstrong, D. M. Universals: An Opinionated Introduction. Boulder [etc.]: Westview, 1989.

Cita MLA (9a ed.)

Armstrong, D. M. Universals: An Opinionated Introduction. Westview, 1989.