Perhaps you should try some spelling variations:
national investment » international investment, capital investment, national treatment
investment serie » investment series, investment syria, investment services
development cass » development cases, development case, development cash
serie series » series series, services series, price series
cass series » class series, laws series, maps series

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: (( national investment serie series ) OR ( industrial development cass series ))~.
• Adding a wildcard symbol may retrieve word variants: (( national investment serie series ) or ( industrial development cass series ))*.