Perhaps you should try some spelling variations:
investment periods » investment period, investment series, investment operations
investments flows » investment flows, investment flow, investments laws
heat sector » meat sector, health sector, heating sector
ment water » most water, peat water, want water
melt water » salt water

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 sector investment periods ) OR ( h. ((ment water) OR (melt water)) investments flows ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( h. heat sector investment periods ) or ( h. ((ment water) OR (melt water)) investments flows ))~".
• Adding a wildcard symbol may retrieve word variants: (( h. heat sector investment periods ) or ( h. ((ment water) OR (melt water)) investments flows ))*.