Akhmad, Y., M. Masrukhi, and B. Indiatmoko. “The Effectiveness of the Integrated Project-Based Learning Model STEM to Improve the Critical Thinking Skills of Elementary School Students”. Educational Management, Vol. 9, no. 1, Dec. 2019, pp. 9-16, https://journal.unnes.ac.id/sju/eduman/article/view/35870.