Novotná, J., P. Eisenmann, J. Přibyl, J. Ondrušová, and J. Břehovský. “PROBLEM SOLVING IN SCHOOL MATHEMATICS BASED ON HEURISTIC STRATEGIES”. Journal on Efficiency and Responsibility in Education and Science, vol. 7, no. 1, Mar. 2014, pp. 1-6, doi:10.7160/eriesj.2014.070101.