Perhaps you should try some spelling variations:
regulatory relations » regulatory regions, regular relations, regulatory functions
respiratory setting » respirator settings, respiratory testing, respiratory gating
cycle regulatory » cycle regulation, gene regulatory

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: (( cycle regulatory relations ) OR ( acute respiratory setting )).
• Adding a wildcard symbol may retrieve word variants: (( cycle regulatory relations ) or ( acute respiratory setting ))*.