Perhaps you should try some spelling variations:
"key regulatory perspectives" » "key regulatory perspective", "key regulatory peptides", "key regulator perspectives", "key regulators perspectives", "4 regulatory perspectives"
"3 regulatory properties" » "3 regularity properties", "3 regular properties", "3 regulatory proteins", "law regulatory properties", "3 regulation properties"
"a regulatory properties" » "a regularity properties", "a regular properties", "a regulatory proteins"

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 regulatory perspectives") OR ((("3 regulatory properties") OR ("a regulatory properties"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"key regulatory perspectives\") or (((\"3 regulatory properties\") OR (\"a regulatory properties\"))))*".
• Removing quotes may allow a broader search: (( key regulatory perspectives ) or ((( 3 regulatory properties ) OR ( a regulatory properties ))))*.