Ibrahim Marhoon, Ismail. 2016. “STUDY THE EFFECT OF POLYPROPYLENE FIBERS IN SOME MECHANICAL AND PHYSICAL PROPERTIES OF RIGID POLYURETHANE FOAM COMPOSITES”. Journal of Engineering and Sustainable Development 20 (4): 71-87. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/581.