1. PS-Draft, Delcam Plc, Birmingham. 〈http://www.delcam.com〉.
2. VP HybridCAD, Softelec Corporation, Texas, USA. 〈http://www.hybridcad.com〉.
3. T-CAD, ShoeNet Co. Ltd., Taiwan, ROC. 〈http://www.shoenet.com.tw〉.
4. PCut, Fuzhou University, Fuzhou, China. 〈http://www.ytsd.net/shoesstar〉.
5. Nesting, Fengensoft Co. Ltd., Beijing, China. 〈http://www.yieldworks.com.cn〉.