Azmi, Z.L. et al. 2022. The Validity and Practicality of Student Worksheets on Waves and Sounds for Junior High School Students . Jurnal Penelitian Pendidikan IPA. 8, 4 (Oct. 2022), 1764–1770. DOI:https://doi.org/10.29303/jppipa.v8i4.1797.