Perhaps you should try some spelling variations:
investment period » investment policy, adjustment period, investment operations
investment series » investment services, investment barriers, investment treaties
based investment » best investment, bond investment, related investment
fixed investment » direct investment
test based » text based, rest based, trust based
kept fixed » net fixed

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: (( h. test based investment series ) OR ( h. kept fixed investment period ))~.
• Adding a wildcard symbol may retrieve word variants: (( h. test based investment series ) or ( h. kept fixed investment period ))*.