With the asterisk * at the end of your search term you are able to find all possible endings. Without the asterisk only the accurate term will be searched. Plural forms etc. will not be regarded.
competit* = competition, competitive, …
Put multiple search terms, directly referring to each other, in quotation marks. This is especially useful, if both search terms occur quite often individually:
Use our STW Thesaurus for Economics, to identify the best search terms. The Thesaurus is a web of broader and narrower terms, related terms, synonyms and translations. With terms from the STW you will find the best results in EconBiz.
In EconBiz you can find many freely available online publications. Check the box "Open Access material only" below the search field to limit your search to such free full texts.