Sitorus, Grace Elicia, Martha Indah Samosir, Prihatin Ningsih Sagala, Khoirunnisa Sibarani, Nadira Kaylana Dhuha, and Tiolina Maria Munthe. “Hubungan Kualitas Tidur Terhadap Konsentrasi Belajar Matematika Siswa Kelas VII-3 SMPN 4 Medan”. Mandalika Mathematics and Educations Journal 7, no. 1 (March 29, 2025): 204–219. Accessed April 6, 2025. http://jurnalfkip.unram.ac.id/index.php/MANDALIKA/article/view/8790.