TY  - RPRT
TI  - System for preparation of known concentrations of methane in air 
AU  - Hughes, Ernest E
AU  - Dorko, William D
AU  - Taylor, John K
PY  - 1973
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS IR 73-255
DO  - 10.6028/NBS.IR.73-255
ER  -