1. Entry
     CDA Reference (2.16.840.1.113883.10.12.324)
    1. Entry
       CDA ExternalAct (2.16.840.1.113883.10.12.325)
    2. Entry
       CDA ExternalObservation (2.16.840.1.113883.10.12.326)
    3. Entry
       CDA ExternalProcedure (2.16.840.1.113883.10.12.327)
    4. Entry
       CDA ExternalDocument (2.16.840.1.113883.10.12.328)