Zejnilagić-Hajrić M, Šabeta A, Nuić I. The effects of problem-based learning on students’ achievements in primary school chemistry. Glas. hem. tehnol. Bosne Herceg. 2015;44:17-22. Accessed August 30, 2026. https://glashem.pmf.unsa.ba/index.php/bctbh/article/view/142