Perhaps you should try some spelling variations:
"digitalia book collection: lom edicion." » "digitalia ebook collection: lom edicion.", "digitalia book collecting: lom edicion.", "digitalia book collectors: lom edicion.", "digitalia book collection: lom ediciones.", "digitalia book collection: la edicion.", "digitalia book collection: con edicion."
"digitalia book collection: las mediciones." » "digitalia ebook collection: las mediciones.", "digitalia book collecting: las mediciones.", "digitalia book collectors: las mediciones.", "digitalia book collection: las mediaciones.", "digitalia book collection: las ediciones.", "digitalia book collection: las condiciones."

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 book collection: lom edicion.") or ("digitalia book collection: las mediciones."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("digitalia book collection: lom edicion.") OR ("digitalia book collection: las mediciones.")).
• Removing quotes may allow a broader search: (( digitalia book collection: lom edicion. ) or ( digitalia book collection: las mediciones. )).
• Adding a wildcard symbol may retrieve word variants: (("digitalia book collection: lom edicion.") or ("digitalia book collection: las mediciones."))*.