TY  - BOOK
AU  - H,R. Langman
TI  - How to make working diagram models
U1  - 621.3 
PY  - 1939///
CY  - London
PB  - The technical press ltd.
KW  - MCE
N1  - 0; 0; 0; 621_300000000000000_LAN; 0; 0; 0; 621_313300000000000_LAN
ER  -