Organisation for Economic Co-operation and Development. (2017). The nature of problem solving: Using research to inspire 21st century learning. OECD.
Παραπομπή σε μορφή Chicago (17η εκδ.)Organisation for Economic Co-operation and Development. The Nature of Problem Solving: Using Research to Inspire 21st Century Learning. Paris: OECD, 2017.
Παραπομπή σε μορφή MLA (9th εκδ.)Organisation for Economic Co-operation and Development. The Nature of Problem Solving: Using Research to Inspire 21st Century Learning. OECD, 2017.
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