Perhaps you should try some spelling variations:
fixed investment » direct investment
investment ties » investment series, investment trends, investment trust
net investment » debt investment, direct investment, forest investment
testing fixed » testing field, trading fixed, voting fixed
test net » test nat, test test, test bed

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( h. test net investment ties ) or ( h. testing fixed investment barriers ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( h. test net investment ties ) OR ( h. testing fixed investment barriers )).
• Adding a wildcard symbol may retrieve word variants: (( h. test net investment ties ) or ( h. testing fixed investment barriers ))*.