Spychaj, T., and R. Pilawka. “The Physicochemical Characterization of an Aminoester-Type Epoxy-Resin Hardener Prepared from Chemical Degradation of poly(ethylene Terephthalate)”. Polimery, vol. 46, no. 11-12, Sept. 2022, pp. 803-11, https://ichp.vot.pl/index.php/p/article/view/2136.