TY  - RPRT
TI  - Improved ultrasonic standard reference blocks
AU  - Eitzen, D. G.
AU  - Sushinsky, G. F.
AU  - Chwirut, D. J.
AU  - Bechtoldt, C. J.
AU  - Ruff, A. W.
PY  - 1976
UR  - https://ntrs.nasa.gov/citations/19770006493
ID  - 19770006493
ER  -