Pólya, G. (1957). How to solve it: A new aspect of mathematical method (2a ed.). Doubleday.
Cita Chicago Style (17a ed.)Pólya, George. How to Solve It: A New Aspect of Mathematical Method. 2a ed. Garden City, New York: Doubleday, 1957.
Cita MLA (8a ed.)Pólya, George. How to Solve It: A New Aspect of Mathematical Method. 2a ed. Doubleday, 1957.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.