Perhaps you should try some spelling variations:
investment demand » investor demand
rates investment » notes investment, rules investment, water investment
based investment » fixed investment, best investment, bond investment
investment rate » investment climate
heat rates » heat rate, death rates, heat waves
test based » text based, rest based, trust based

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. heat rates investment rate ) OR ( h. test based investment demand ))~.
• Adding a wildcard symbol may retrieve word variants: (( h. heat rates investment rate ) or ( h. test based investment demand ))*.