Perhaps you should try some spelling variations:
economics agency » economic agency, economic agents, economics science
recherche land » recherche dans, recherche prend, recherches dans
economic agent » economic agents, economic rent, economic rents
recherche und » recherche en, recherche d'une, recherche prend
studi e » studi per, studia ve, studie 2

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

• Performing a fuzzy search may retrieve terms with similar spellings: studi e ((recherche land) or (recherche und)) ((economics agency) OR (economic agent)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: studi e ((recherche land) OR (recherche und)) ((economics agency) OR (economic agent)) ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "studi e ((recherche land) or (recherche und)) ((economics agency) OR (economic agent)) ;*".