1. Accuracy test of five-axis CNC machine tool with 3D probe-ball, Part I: design and modelling;Lei;International Journal of Machine Tools & Manufacture,2002
2. ISO 10791 series, 1998, Test conditions for machining centres, ISO, Geneva
3. Unification Document Me: Axes of Rotation;Annals of the CIRP,1976
4. www.fidia.de < Produkte < HMS hms_ted.pdf, as presented on 12-20-2003
5. EN ISO 10360-3: 2000, Acceptance and reverification tests for coordinate measuring machines (CMM) -Part 3: CMMs with the axis of rotation as the fourth axis, CEN, Brussels