+ <xs:sequence>
+ <xs:element name="dbRef" minOccurs="0" maxOccurs="unbounded">
+ <xs:complexType>
+ <xs:attribute name="source"/>
+ <xs:attribute name="version"/>
+ <xs:attribute name="accessionId"/>
+ <xs:attribute name="id" type="xs:ID" minOccurs="0" maxOccurs="1"/>
+ </xs:complexType>
+ </xs:element>
+ </xs:sequence>
+ <xs:attribute name="id" type="xs:ID" minOccurs="1" maxOccurs="1"/>