TY  - RPRT
TI  - Guidelines for selection of and use of foam polyurethane roofing systems 
AU  - Cullen, William C
PY  - 1973
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 778
DO  - 10.6028/NBS.TN.778
ER  -