Perhaps you should try some spelling variations:
"digitalia book collection: del editor." » "digitalia ebook collection: del editor.", "digitalia book collecting: del editor.", "digitalia book collectors: del editor."
"digitalia book collection: del escritor." » "digitalia ebook collection: del escritor.", "digitalia book collecting: del escritor.", "digitalia book collectors: del escritor.", "digitalia book collection: un escritor."

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: del editor.") OR ("digitalia book collection: del escritor."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"digitalia book collection: del editor.\") OR (\"digitalia book collection: del escritor.\"))".
• Removing quotes may allow a broader search: (( digitalia book collection: del editor. ) OR ( digitalia book collection: del escritor. )).
• Adding a wildcard symbol may retrieve word variants: (("digitalia book collection: del editor.") OR ("digitalia book collection: del escritor."))*.