Perhaps you should try some spelling variations:
related investment » private investment, estate investment, bilateral investment
investment period » investment series, investment policy, investment demand
investment costs » investment funds, investment flows, investment banks
road investment » fixed investment
heat related » health related, heat rate, heat rates

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. agent road investment period ) OR ( h. heat related investment costs ))~.
• Adding a wildcard symbol may retrieve word variants: (( h. agent road investment period ) or ( h. heat related investment costs ))*.