Frege, G. (1980). Philosophical and mathematical correspondence. The University of Chicago.
Lua i Stíl Chicago (17ú heag.)Frege, Gottlob. Philosophical and Mathematical Correspondence. Chicago: The University of Chicago, 1980.
Lua MLA (9ú heag.)Frege, Gottlob. Philosophical and Mathematical Correspondence. The University of Chicago, 1980.
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