Raffania Arsyila Disyah, Nabila Zahra Syaeli, Razi Dahlan, Muhammad Nabil Akbar, and Risna Mira Bella Saragih, “THE EFFECT OF SLEEP PATTERNS ON LEARNING CONCENTRATION OF GRADE XII STUDENTS OF AL AZHAR MEDAN OUTSTANDING HIGH SCHOOL”, BESTI, vol. 4, no. 4, pp. 2243–2250, Oct. 2026.