ibooks duplicate itemref

I want to show the same xhtml file in several positions in my book. Therefore, duplication de itemref in spine don't work in iBooks. Only the first itemref is showed in iBooks. E.g.:

<spine toc="ncx">

<itemref idref="BackC" />

<itemref idref="BackD" />

<itemref idref="BackC" />

<itemref idref="BackD" />

</spine>

I tried to declare linear="yes", or declare properties="page-spread-left", or declare the id to every itemref, but none of it work.

How can I show one xhtml file in several positions along the ebook?