Yulanda, Vera, Afreni Hamidah, and Evita Anggereini. 2023. “Development of Electronic Student Worksheets (E-LKPD) Based on Problem Based Learning As an Effort to Improve Critical Thinking of Grade VIII Middle School Students on Respiratory System Material”. Jurnal Penelitian Pendidikan IPA 9 (9):7326-32. https://doi.org/10.29303/jppipa.v9i9.4144.