Giblin, P., & Porteous, I. (1994). Challenging mathematics: A selection of secondary school mathematics problems. Oxford: Oxford University Press.
Παραπομπή Chicago StyleGiblin, Peter, and Ian Porteous. Challenging Mathematics: A Selection of Secondary School Mathematics Problems. Oxford: Oxford University Press, 1994.
Παραπομπή MLAGiblin, Peter, and Ian Porteous. Challenging Mathematics: A Selection of Secondary School Mathematics Problems. Oxford: Oxford University Press, 1994.
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