Gultom, Dahlia, dan Syarifuddin Syarifuddin. 2016. “THE COMPLETENESS, BREADTH AND DEPTH : A COMPARISON BETWEEN INDONESIAN AND CAMBRIDGE HIGH SCHOOL BIOLOGY TEXTBOOKS FOR CIRCULATORY SYSTEM”. Jurnal Pelita Pendidikan 4 (3). https://doi.org/10.24114/jpp.v4i3.6625.