“Potential of Beetroot (Beta Vulgaris L.) and Purple Sweet Potato (Ipomoea Batatas L.) As Natural Indicators of Formalin in Food”. 2019. Jurnal Ilmu Kesehatan Bhakti Setya Medika 4 (September): 7-13. https://doi.org/10.56727/bsm.v4i.67.