APA (7th ed.) Citation

Penrose, R., & Gardner, p. M. (1997). A mente virtual (1<U+00AA> ed.). Gradiva.

Chicago Style (17th ed.) Citation

Penrose, Roger, and pref. Martin Gardner. A Mente Virtual. 1<U+00AA> ed. Gradiva, 1997.

MLA (8th ed.) Citation

Penrose, Roger, and pref. Martin Gardner. A Mente Virtual. 1<U+00AA> ed. Gradiva, 1997.

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