Citazione Stile APA (7a Edizione)

Wittgenstein, L. (1958). Preliminary studies for the "philosophical investigations": The blue and brown books. Harper.

Citazione stile Chigago Style (17a edizione)

Wittgenstein, Ludwig. Preliminary Studies for the "Philosophical Investigations": The Blue and Brown Books. New York: Harper, 1958.

Citatione MLA (9a ed.)

Wittgenstein, Ludwig. Preliminary Studies for the "Philosophical Investigations": The Blue and Brown Books. Harper, 1958.