Παραπομπή APA
Birtwistle, C. (1971). Mathematical puzzles and perplexities: How to make the most of them. London: Allen and Unwin.
Παραπομπή Chicago StyleBirtwistle, Claude. Mathematical Puzzles and Perplexities: How to Make the Most of Them. London: Allen and Unwin, 1971.
Παραπομπή MLABirtwistle, Claude. Mathematical Puzzles and Perplexities: How to Make the Most of Them. London: Allen and Unwin, 1971.
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