Holton, D. (2011). Second step to mathematical olympiad problems. World Scientific Publishing.
शिकागो स्टाइल उद्धरणHolton, Derek. Second Step to Mathematical Olympiad Problems. Singapore: World Scientific Publishing, 2011.
एमएलए उद्धरणHolton, Derek. Second Step to Mathematical Olympiad Problems. World Scientific Publishing, 2011.
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