Corredor de Porras, M. (2011). Cognitive instruments in mathematical thinking summary. Universidad Pedagógica y Tecnológica de Colombia.
Čikaški stil citiranja (17. izdanje)Corredor de Porras, Magally. Cognitive Instruments in Mathematical Thinking Summary. Universidad Pedagógica y Tecnológica de Colombia, 2011.
MLA način citiranja (9. izdanje)Corredor de Porras, Magally. Cognitive Instruments in Mathematical Thinking Summary. Universidad Pedagógica y Tecnológica de Colombia, 2011.
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