TY  - RPRT
TI  - Circular of the Bureau of Standards no. 552 3rd edition: standard materials issued by the National Bureau of Standards
PY  - 1959
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS CIRC 552e3
DO  - 10.6028/NBS.CIRC.552e3
ER  -