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

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

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