Wittgenstein, L. (1958). Preliminary studies for the "philosophical investigations": The blue and brown books. Harper.
Lua i Stíl Chicago (17ú heag.)Wittgenstein, Ludwig. Preliminary Studies for the "Philosophical Investigations": The Blue and Brown Books. New York: Harper, 1958.
Lua MLA (9ú heag.)Wittgenstein, Ludwig. Preliminary Studies for the "Philosophical Investigations": The Blue and Brown Books. Harper, 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.