Não informado. (1979). Focus on Learning Problems in Mathematics. Center for Teaching Learning on Mathematics.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Focus on Learning Problems in Mathematics. Framingham, Mass: Center for Teaching Learning on Mathematics, 1979.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Focus on Learning Problems in Mathematics. Center for Teaching Learning on Mathematics, 1979.
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