1. The gerber format specification: Rs-274x or extended gerber, revision h (Jan 2012). URL www.ucamco.com/public/RS-274X Extended Gerber Format Specification 201201.pdf .
2. K. Tavernier, Improving cad to cam data transfer a practical approach, Journal of the HKPCA 40 (2011) 14-18. URL www.ucamco.com/downloads/Improving CAD to CAM Data Transfer 201110.pdf .