1. Automated conversion of existing mechanical engineering drawings to CAD data structures: state of the art;Hofer-Alfeis,1986
2. Initial Graphics Exchange Specification (IGES),1986
3. Computer processing of line images: a survey;Smith;Pattern Recognition,1987
4. The Fastrak automatic digitizing system;Fulford;Pattern Recognition,1981
5. An automatic digitizing system for line drawings;Nackunstz,1982