1. Hail resistance of roofing products
2. . 8. Crenshaw, V., and. J. D. Koontz. "Simulated. Hail. Damage. and. Impact. Test. Resistance. Test. Procedures. For. Roof. Coverings. and. Membranes.". Presented. at. the. Third. International. Symposium.on.Roofing.Technology,April.1991.