Perhaps you should try some spelling variations:
"comercio del marketing." » "comercio de marketing.", "comercio y marketing.", "comercial de marketing."
"comercio en marketing." » "comercio el marketing.", "comercio de marketing.", "comercio y marketing.", "comercial en marketing.", "comercio den marketing.", "comercio yn marketing."
"comercio e marketing." » "comercio de marketing.", "comercio el marketing.", "comercio y marketing."

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: (("comercio en marketing.") or ((("comercio del marketing.") OR ("comercio e marketing."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("comercio en marketing.") OR ((("comercio del marketing.") OR ("comercio e marketing.")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"comercio en marketing.\") or (((\"comercio del marketing.\") OR (\"comercio e marketing.\"))))".
• Removing quotes may allow a broader search: (( comercio en marketing. ) or ((( comercio del marketing. ) OR ( comercio e marketing. )))).
• Adding a wildcard symbol may retrieve word variants: (("comercio en marketing.") or ((("comercio del marketing.") OR ("comercio e marketing."))))*.