Phu, Dang Van, et al. “Preparation and Foliar Application of Oligochitosan - Nanosilica on the Enhancement of Soybean Seed Yield.” International Journal of Environment, Agriculture and Biotechnology, vol. 2, no. 1, 2017, pp. 421–28. Crossref, https://doi.org/10.22161/ijeab/2.1.53.