1. Ryman A. , Weerawarana S. , Moreau J.-J. and Chinnici R. , Web services description language (WSDL) version 2.0 part 1: Core language, W3C recommendation, W3C, (2007). http://www.w3.org/TR/2007/REC-wsdl20-20070626.
2. Booth D. , Haas H. , McCabe F. , Ferris C. , Champion M. , Orchard D. and Newcomer E. , Web services architecture, W3C note, W3C, (2004). http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/.
3. Mani A. and Nagarajan A. , Understanding quality of service for web services, https://www.ibm.com/developerworks/java/library/ws-quality/.
4. Farrell J. and Lausen H. , Semantic annotations for WSDL and XML schema, W3C recommendation, W3C, (2007) http://www.w3.org/TR/2007/REC-sawsdl-20070828/.