Perhaps you should try some spelling variations:
"digitalia ebooks collection: con mediacion." » "digitalia book collecting: con mediacion.", "digitalia ebooks collection: co mediacion.", "digitalia ebooks collection: como mediacion.", "digitalia ebooks collection: con radiacion.", "digitalia books collection: con mediacion."
"digitalia ebook collection: lom ediciones." » "digitalia book collection: lom ediciones.", "digitalia ebook collection: lom edicion."

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("digitalia ebooks collection: con mediacion.") or ("digitalia ebook collection: lom ediciones."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("digitalia ebooks collection: con mediacion.") OR ("digitalia ebook collection: lom ediciones.")).
• Removing quotes may allow a broader search: (( digitalia ebooks collection: con mediacion. ) or ( digitalia ebook collection: lom ediciones. )).
• Adding a wildcard symbol may retrieve word variants: (("digitalia ebooks collection: con mediacion.") or ("digitalia ebook collection: lom ediciones."))*.