Cita APA (7a ed.)

Pólya, G. (1990). How to solve it: A new aspect of mathematical method (2nd ed.). Penguin Books.

Cita Chicago Style (17a ed.)

Pólya, George. How to Solve It: A New Aspect of Mathematical Method. 2nd ed. Harmondsworth, Middlesex: Penguin Books, 1990.

Cita MLA (9a ed.)

Pólya, George. How to Solve It: A New Aspect of Mathematical Method. 2nd ed. Penguin Books, 1990.