Beck, L. W., & Holmes, R. L. (1968). Philosophic inquiry: An introduction to philosophy. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Beck, Lewis White, agus Robert L. Holmes. Philosophic Inquiry: An Introduction to Philosophy. Englewood Cliffs, N.J: Prentice-Hall, 1968.
Lua MLA (9ú heag.)Beck, Lewis White, agus Robert L. Holmes. Philosophic Inquiry: An Introduction to Philosophy. Prentice-Hall, 1968.
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