Mustikawati, Dewi Rumbaina, et al. “Study Effectiveness of Liquid Smoke As a Natural Insecticide for Main Pest Control of Soybean Crops”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 30, no. 1, Oct. 2016, pp. 237-45, https://gssrr.org/JournalOfBasicAndApplied/article/view/6363.