TY  - BOOK
ED  - National Geographic Society (U.S.).
TI  - The Builders: marvels of engineering 
SN  - 0870448366
AV  - TA15 .B85 1992
U1  - 620 20
PY  - 1992///
CY  - Washington, DC
PB  - The Society
KW  - Engineering
KW  - History
N1  - Includes index
UR  - http://www.archive.org/details/buildersmarvelso00nati
UR  - http://www.openlibrary.org/books/OL1726529M
ER  -