Kashiwagi, Dean, Dhaval Gajjar, Jacob Kashiwagi, and Kenneth Sullivan. “Hail Study on a 15 Year Old Sprayed Polyurethane Foam Roofing System”. Journal for the Advancement of Performance Information and Value 8, no. 1 (June 1, 2016): 5–1 . Accessed November 23, 2024. http://journal.cibw117.org/index.php/japiv/article/view/47.