Perhaps you should try some spelling variations:
"population ; apercus economiques" » "population ; aspects economiques", "population ; arts economiques", "population ; reperes economiques"
"population ; espaces economiques" » "population ; espace economique", "population ; aspects economiques", "population ; etudes economiques"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("population ; apercus economiques") OR ("population ; espaces economiques")).
• Removing quotes may allow a broader search: (( population ; apercus economiques ) or ( population ; espaces economiques )).
• Adding a wildcard symbol may retrieve word variants: (("population ; apercus economiques") or ("population ; espaces economiques"))*.