Perhaps you should try some spelling variations:
investment operations » investment options, investment corporation, investment regulations
rates investment » notes investment, rules investment, water investment
rate payment » rate payments, late payment, late payments
heat rates » heat rate, death rates, heat waves
dept rate » heat rate, deposit rate

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( h. heat rates investment operations ) or ( h. dept rate payment services ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( h. heat rates investment operations ) OR ( h. dept rate payment services )).
• Adding a wildcard symbol may retrieve word variants: (( h. heat rates investment operations ) or ( h. dept rate payment services ))*.