TY  - BOOK
AU  - O' Brien Robert.
TI  - Machines
T2  - Life Science Library
U1  - R 621-8 L2 
PY  - 1972///
CY  - New York
PB  - Time-Life Books
KW  -  Robert O' Brien and the editors of time-life books
KW  - Machinery
ER  -