Cita APA (7a ed.)

Wittgenstein, L., McGuinness, B., Nyberg, T., Wright, G. H. v., & Pears, D. F. (1971). Prototractatus: An early version of Tractatus logico-philosophicus. Routledge & Kegan Paul.

Cita Chicago Style (17a ed.)

Wittgenstein, Ludwig, Brian McGuinness, T. Nyberg, G. H. von Wright, y David Francis Pears. Prototractatus: An Early Version of Tractatus Logico-philosophicus. London: Routledge & Kegan Paul, 1971.

Cita MLA (9a ed.)

Wittgenstein, Ludwig, et al. Prototractatus: An Early Version of Tractatus Logico-philosophicus. Routledge & Kegan Paul, 1971.