TY  - BOOK
AU  - Frances Gies 
AU  - Joseph Gies
TI  - Cathedral, forge, and waterwheel: : technology and invention in the Middle Ages
SN  - 0060165901
PY  - 1994///
CY  - San Francisco
PB  - HarperCollins Publishers
KW  - Technology
KW  - History
ER  -