Perhaps you should try some spelling variations:
"digitalia book collection: el viaje loco." » "digitalia ebook collection: el viaje loco.", "digitalia book collecting: el viaje loco.", "digitalia book collectors: el viaje loco.", "digitalia book collection: el viaje como.", "digitalia book collection: el viaje los.", "digitalia book collection: el viaje tomo."
"digitalia book collection: el viejo celoso." » "digitalia ebook collection: el viejo celoso.", "digitalia book collecting: el viejo celoso.", "digitalia book collectors: el viejo celoso.", "digitalia book collection: el viejo celso.", "digitalia book collection: el viejo celos."

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