Handle multivolume TEI files

As the title says. There may be works that are distributed over several files, e.g. Vitoria's Relectiones:

<TEI xmlns="http://www.tei-c.org/ns/1.0" xmlns:xi="http://www.w3.org/2001/XInclude" xml:id="W0013">
    <teiHeader/>
    <text xml:lang="la" type="work_multivolume" xml:id="completeWork">
        <group>
            <xi:include href="W0013_Vol01.xml" xpointer="Vol01">
                <xi:fallback>
                    <p xml:lang="de">Band 1 konnte nicht eingebunden werden.</p>
                </xi:fallback>
            </xi:include>
            <xi:include href="W0013_Vol02.xml" xpointer="Vol02">
                <xi:fallback>
                    <p xml:lang="de">Band 2 konnte nicht eingebunden werden.</p>
                </xi:fallback>
            </xi:include>
        </group>
    </text>     
</TEI>

It would be desirable to have one deposit per-multivolume work containing several XML files...