TY  - BOOK
AU  - Graf, Rudolf F. and Whalen, George J.
TI  - How it works, illustrated: : everyday devices and mechanisms
SN  - 0285621734
U1  - 621 
PY  - 1974///
CY  - London
PB  - ; Popular Science
KW  - Engineering
KW  - Mechanical Engineering
ER  -