Sugiharto, Sony, et al. “The Correlation of BRCA 1 Promoter Methylation and Clinicopathological Appearance in Breast Cancer”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 41, no. 1, Aug. 2018, pp. 51-60, https://gssrr.org/JournalOfBasicAndApplied/article/view/9275.