[1] http://www.veloconnect.de
[2] http://www.oasis-open.org
[3] http://docs.oasis-open.org/ubl/cd-UBL-1.0/
[4] http://www.vsf.de
[5] http://www.w3.org/TR/2004/REC-xml-20040204/
[6] http://www.w3.org/TR/xmlschema-1/
[7] http://www.w3.org/TR/1999/REC-xml-names-19990114/
[8] http://www.w3.org/Protocols/rfc2616/rfc2616.txt
[9] http://www.faqs.org/rfcs/rfc2818.html