TY  - RPRT
TI  - Circular of the Bureau of Standards no. 156: United States government specification for coal-tar saturated rag felt for roofing and waterproofing
PY  - 1924
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS CIRC 156
DO  - 10.6028/NBS.CIRC.156
ER  -