Those elements that may mix with data characters inside a <citation> element
<!ENTITY % citation-elements
"| %article-link.class; | %appearance.class; |
%emphasis.class; | %inline-display.class; |
%inline-math.class; | %label.class; |
%math.class; | %phrase.class; |
%references.class; | %simple-link.class; |
%subsup.class; | %x.class;" >archivecustom-models.ent