Muarif, Muarif, et al. “A Framework for Screening of Variables of Ecological Sensitivity Index (ESI) of Mangrove Ecosystems to Oil Spills”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 27, no. 1, May 2016, pp. 142-53, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/5638.