Bajer, K., R. Malinowski, D. Bajer, and S. Richert. “Properties of poly(lactic acid)/Ecoflex Rigid Foil Sheets Applied in Thermof Orming Process”. Polimery, vol. 55, no. 7-8, Aug. 2010, pp. 591-3, https://ichp.vot.pl/index.php/p/article/view/1045.