Siswoyo S. Development of Teacher Guidebook for Photoelectric Effects Instructional Using Predict-Observe-Explain Strategy with PhET Interactive Simulation. jpppf [Internet]. 2019Nov.5 [cited 2025Jun.9];5(2):133 -144. Available from: http://103.8.12.212:33180/unj/index.php/jpppf/article/view/12754