Não informado. (1970). Journal for Research in Mathematics Education. National Council of Teachers of Mathematics.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Journal for Research in Mathematics Education. Reston, Va: National Council of Teachers of Mathematics, 1970.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Journal for Research in Mathematics Education. National Council of Teachers of Mathematics, 1970.
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