The nature of problem solving : using research to inspire 21st century learning. Edited by: Benő Csapó and Joachim Funke. Paris : OECD, 2017. 270 s. Educational research and innovation. Available on Internet: <http://www.oecd-ilibrary.org/education/the-nature-of-problem-solving_9789264273955-en> ISBN 978-92-64-24753-6.