Liszkowska, J., B. Czupryński, and J. Paciorek-Sadowska. 2021. “Temperature Stability and Thermal Properties of Polyurethane-Polyisocyanurate Foams Obtained Using Products of Citric Acid Condensation”. Polimery 63 (7-8):503-14. https://doi.org/10.14314/polimery.2018.7.4.