Pandiangan, Paken. “The Practicality and Effectiveness of the Physics Independent Learning (PIL) Model Toolkit in Online Tutorials to Improve Physics Independent Learning Skills and Physics Problem-Solving Skills”. Jurnal Penelitian Pendidikan IPA, vol. 9, no. 5, May 2023, pp. 4008-14, doi:10.29303/jppipa.v9i5.3711.