TY  - RPRT
TI  - Procedures for the calibration of ASTM E127-Type ultrasonic reference blocks 
AU  - Chwirut, D J
PY  - 1976
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 924
DO  - 10.6028/NBS.TN.924
ER  -