Amelia A. Lewis; Bijan Parsia. <a href="http://www.w3.org/TR/2005/NOTE-wsdl20-altschemalangs-20050817"><cite>Discussion of Alternative Schema Languages and Type System Support in WSDL 2.0.</cite></a> 17 August 2005. W3C Note. URL: <a href="http://www.w3.org/TR/2005/NOTE-wsdl20-altschemalangs-20050817">http://www.w3.org/TR/2005/NOTE-wsdl20-altschemalangs-20050817</a>