Pólya, G. (1981). Mathematical discovery: On understanding, learning, and teaching problem solving (Combined ed.). Wiley.
Chicago-viite (17. p.)Pólya, George. Mathematical Discovery: On Understanding, Learning, and Teaching Problem Solving. Combined ed. New York: Wiley, 1981.
MLA-viite (9. p.)Pólya, George. Mathematical Discovery: On Understanding, Learning, and Teaching Problem Solving. Combined ed. Wiley, 1981.
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