S. A. Daud, M. Jamhari, and L. N. Tangge, “Development of Problem-based Learning Tools to Improve Critical Thinking Skills and Collaboration Skills of Class VIII Junior School Students”, Int. J. Educ. Hum. Soc. Stud., vol. 1, no. 2, pp. 84–93, Sep. 2024, doi: 10.63895/j30321271.2024.v1.i2.pp84-93.