Gong, W., J. Yu, H. Fu, C. Zhang, and L. He. “Strengthening and Toughening Mechanisms for polypropylene/Glass Fiber Composite Foams under Three-Phase Coexistence”. Polimery, vol. 60, no. 7-8, Aug. 2015, pp. 457-61, doi:10.14314/polimery.2015.457.