TY  - BOOK
AU  - Townsend 
TI  - Steel square : use of the scales roof framing illustrative problems other uses 
SN  - 0826906850 
U1  - 694 TOW 1939 
PY  - 1939///
CY  - Illinois
PB  - American Technical
KW  - Books
KW  - Carpenters' squares
ER  -