<https://www.omg.org/spec/NIEM-UML/About-NIEM-UML/>
<http://www.w3.org/2000/01/rdf-schema#label>
"About the UML Profile for NIEM Specification Version 3.0 beta"
<https://www.omg.org/spec/NIEM-UML/3.0/Beta1/>