TY  - BOOK
AU  - Head, George O
TI  - Autocad productivity book : the non-programmer's guide to customizing autocad--for release 13 for windows /  James L. Brittain, George O. Head & A. Ted Schaefer..- 6th ed
SN  - 1566041856
U1  - 620.0042 HEA 
CY  - Chapel Hill, NC : Ventana Press, C1994.
KW  - Systems engineering-mathematical models
ER  -