Cita APA (7a ed.)

Wittgenstein, L. (1987). Preliminary studies for the Philosophical investigations, generally known as the Blue and Brown books (2nd ed.). Basil Blackwell.

Cita Chicago Style (17a ed.)

Wittgenstein, Ludwig. Preliminary Studies for the Philosophical Investigations, Generally Known as the Blue and Brown Books. 2nd ed. Oxford: Basil Blackwell, 1987.

Cita MLA (9a ed.)

Wittgenstein, Ludwig. Preliminary Studies for the Philosophical Investigations, Generally Known as the Blue and Brown Books. 2nd ed. Basil Blackwell, 1987.