TY  - RPRT
TI  - Certification of NBS SRM 1691: 0.3�m-diameter polystyrene spheres 
AU  - Lettieri, Thomas R
AU  - Hembree, Gary G
PY  - 1988
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS IR 87-3730
DO  - 10.6028/NBS.IR.87-3730
ER  -