TY  - RPRT
TI  - "Crawler mounted, revolving power shovels, lifting cranes, dragline and clamshell excavators (export classification)" 
PY  - 1941
PB  - National Bureau of Standards
CY  - "Gaithersburg, MD
SN  - NBS CS 90E-41
DO  - 10.6028/NBS.CS.90E-41
ER  -