TY - GEN AU - Greenfeld, Sidney H C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1968-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.RPT.9871 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1968 TI - Hail resistance of roofing products: ER -