TY  - RPRT
TI  - Letter Circular 559: the certification plan its significance, scope and application to selected Federal specifications and commercial standards
PY  - 1939
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 559
DO  - 10.6028/NBS.LCIRC.559
ER  -