Muh. Takdir. “THE PRINCIPAL ROLE IN IMPROVING STUDENT LEARNING ACHIEVEMENT AT SMPN 01 CIBINONG OF BOGOR DISTRICT”. JELLi Journal, vol. 4, no. 2, Sept. 2021, pp. 28-39, https://journal.umbogorraya.ac.id/index.php/englishforum/article/view/205.