Kucińska-Lipka, J., I. Gubańska, and H. Janik. 2013. “Polyurethanes Modified With Natural Polymers for Medical Application. Part 1. Polyuretane Chitosan and Polyurethane Collagen”. Polimery 58 (9):678-84. https://ichp.vot.pl/index.php/p/article/view/776.