Hutagaol, Ricson P., and Niken Niken. “VALIDASI METODE PENETAPAN KADAR CYANOCOBALAMIN SECARA SPEKTROFOTOMETRI VISIBEL DOUBLE BEAM”. Sains Natural: Journal of Biology and Chemistry 2, no. 1 (November 25, 2017): 24–34. Accessed April 30, 2026. https://ejournalunb.ac.id/JSN/article/view/32.