Fogelin, R. J. (2002). Wittgenstein. Routledge.
Lua i Stíl Chicago (17ú heag.)Fogelin, Robert J. Wittgenstein. London ; New York: Routledge, 2002.
Lua MLA (9ú heag.)Fogelin, Robert J. Wittgenstein. Routledge, 2002.
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