Willoughby, S. S. (1967). Contemporary teaching of secondary school mathematics. New York: Wiley.
Čikaški stil citiranjaWilloughby, Stephen S. Contemporary Teaching of Secondary School Mathematics. New York: Wiley, 1967.
MLA način citiranjaWilloughby, Stephen S. Contemporary Teaching of Secondary School Mathematics. New York: Wiley, 1967.
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