Nasution, Afra Meutia, and Haflin Soraya Hutagalung. “Relationship Between Stress Level of USU Faculty of Medicine Students and Primary Headache During Online Lectures”. Sumatera Medical Journal 6, no. 1 (March 2, 2023): 38–43. Accessed August 5, 2025. https://idjpcr.usu.ac.id/smj/article/view/7943.