Nguyễn, H. T. M., D. Hoang, and T. C. Phạm. “Study of Flame Retardancy, Thermal and Physical Properties of Rigid Polyurethane Foam Based on Recycled Poly(ethylene Terephthalate) Using Non-Halogen Flame Retardant”. Science & Technology Development Journal: Natural Sciences, Vol. 5, no. 2, Apr. 2021, pp. 1189-97, doi:https://doi.org/10.32508/stdjns.v5i2.1011.