APA (7th ed.) Citation

Wittgenstein, L. (1969). The Blue and brown books: Preliminary studies for the 'Philosophical investigations' (2nd ed.). Blackwell.

Chicago Style (17th ed.) Citation

Wittgenstein, Ludwig. The Blue and Brown Books: Preliminary Studies for the 'Philosophical Investigations'. 2nd ed. Oxford: Blackwell, 1969.

MLA (8th ed.) Citation

Wittgenstein, Ludwig. The Blue and Brown Books: Preliminary Studies for the 'Philosophical Investigations'. 2nd ed. Blackwell, 1969.

Warning: These citations may not always be 100% accurate.