ERIC Clearinghouse for Science, Mathematics, and Environmental Education. (1969). Investigations in mathematics education. Leland Stanford Junior University.
Παραπομπή σε μορφή Chicago (17η εκδ.)ERIC Clearinghouse for Science, Mathematics, and Environmental Education. Investigations in Mathematics Education. [Palo Alto?]: Leland Stanford Junior University, 1969.
Παραπομπή σε μορφή MLA (9th εκδ.)ERIC Clearinghouse for Science, Mathematics, and Environmental Education. Investigations in Mathematics Education. Leland Stanford Junior University, 1969.
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