TY  - RPRT
TI  - Circular of the Bureau of Standards no. 171: United States government master specification for the construction of built-up roofing, type 5AWS
PY  - 1924
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS CIRC 171
DO  - 10.6028/NBS.CIRC.171
ER  -