TY  - BOOK
AU  - Machines.
TI  - Understanding science & nature: Machines & inventions
SN  - 0809497042
AV  - TJ 147 .M33 1993 
PY  - 1993///
CY  - Alexandria
PB  - Time life
KW  - Machinery
N1  - Includes bibliographical references and index
ER  -