U. Ruhimat, R. N. . Mutmainah, S. R. K. . Ramdan, and N. R. Firdaus, “Utilization of Purple Sweet Potato Juice As an Alternative Violet Crystal in Coloring Streptococcus sp Bacteria and Escherichia coli”, Jurkes, vol. 11, no. 2, pp. 149–156, Jan. 2025.