Nabila, Putri, et al. “The Strategy of School Heads To Improve The Quality of Learning in 7 State Basic Schools in Kecamatan Air Kumbang”. Jurnal Pendidikan Tambusai, vol. 5, no. 3, Aug. 2021, pp. 5689-95, doi:10.31004/jptam.v5i3.1792.