External module in the base Suite that declares the bibliographic reference elements, i.e., those elements that may appear inside a <element-citation> or <mixed-citation> element.
<!ENTITY % references.ent
PUBLIC
"-//NLM//DTD Archiving and Interchange DTD Suite Bibliographic Reference (Citation) Class Elements v3.0 20080202//EN"
"references3.ent" >modules3.ent