Perhaps you should try some spelling variations:
"key regulators perspectives" » "key regulatory perspectives", "key regulators perspective", "key regulations perspectives", "key regulator perspectives", "_ regulators perspectives"
"_ regulatory properties" » "_ regularity properties", "_ regular properties", "_ regulatory perspectives"
"_ regulation properties" » "_ regulating properties", "_ coagulation properties", "_ granulation properties"

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: (("key regulators perspectives") OR ((("_ regulatory properties") OR ("_ regulation properties"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"key regulators perspectives\") or (((\"_ regulatory properties\") OR (\"_ regulation properties\"))))*".
• Removing quotes may allow a broader search: (( key regulators perspectives ) or ((( _ regulatory properties ) OR ( _ regulation properties ))))*.