Sebastian, R., 		Kuswanto, H., 		Jumadi, J., AND 		Hapsari, N..
"Effectiveness of Flip—Book Optic Devices based on Problem-Based Learning Assisted with Virtual Laboratory Simulation to Improve High School Students’ Visual Representation" <em>Revista Cubana de Física</em> [Online], Volume 40 Number 2 (10 December 2023)