Cita APA (7a ed.)

Wittgenstein, L., Engelmann, P., Furtmuller, L., & Mac Guiness, B. (1967). Letters from Ludwig Wittgenstein: With a memoir. Blackwell.

Cita Chicago Style (17a ed.)

Wittgenstein, Ludwig, Paul Engelmann, L. Furtmuller, y B.F Mac Guiness. Letters from Ludwig Wittgenstein: With a Memoir. Oxford: Blackwell, 1967.

Cita MLA (9a ed.)

Wittgenstein, Ludwig, et al. Letters from Ludwig Wittgenstein: With a Memoir. Blackwell, 1967.