1. ISO, 1994, “Industrial Automation Systems and Integration—Product Data Representation and Exchange—Part 1: Overview and Fundamental Principles,” International Standards Organization, Geneva, Switzerland, Standard No. ISO 10303-1:1994.
2. ISO, 1994, “Industrial Automation Systems and Integration—Product Data Representation and Exchange—Part 203: Application Protocol: Configuration Controlled 3D Designs of Mechanical Parts and Assemblies,” International Standards Organization, Geneva, Switzerland, Standard No. ISO 10303-203:1994.
3. ISO, 1994, “Industrial Automation Systems and Integration—Product Data Representation and Exchange—Part 11: Description Methods: The EXPRESS Language Reference,” International Standards Organization, Geneva, Switzerland, Standard No. ISO 10303-11: 1994.
4. Development of Functionality-Based Conformance Classes for ISO 10303: Conformance Classes for Tolerancing Functionality;Comput.-Aided Des. Appl.,2009
5. The STEP Modular Architecture;ASME J. Comput. Inf. Sci. Eng.,2002