[1]
R. D. . Simorangkir, T. R. A. . Naibaho, P. . Sinambela, and C. T. . Panjaitan, “AN ANALYSIS OF MATERIALS IN A STUDENT TEXTBOOK AT SECONDARY SCHOOL IN 8th GRADE”, JEE, vol. 5, no. 2, pp. 123–129, Dec. 2019.