TY  - BOOK
AU  - Armentrout,Patricia
TI  - The pulley
T2  - Simple devices
SN  - 1571031782
U1  - 621.8 
PY  - 1997///
CY  - Vero Beach, Fla.
PB  - Rourke Press
KW  - Pulleys
N1  - Includes index
N2  - Text and pictures introduce the pulley, a simple machine used primarily to lift heavy objects
ER  -