Perhaps you should try some spelling variations:
"cycle regulatory relations" » "cycle regulatory regions", "cycle regular relations", "cycle regulatory functions", "cycle regulation relations"
"gene regulatory relations" » "gene regulatory regions", "gene regular relations", "gene regulatory functions", "gene regulation relations"
"acute respiratory testing" » "acute respiratory gating", "acute respiratory training", "acute respiratory patterning"

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 ("gene regulatory relations"))) OR ("acute respiratory testing")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"cycle regulatory relations\") OR (\"gene regulatory relations\"))) or (\"acute respiratory testing\"))".
• Removing quotes may allow a broader search: (((( cycle regulatory relations ) OR ( gene regulatory relations ))) or ( acute respiratory testing )).
• Adding a wildcard symbol may retrieve word variants: (((("cycle regulatory relations") OR ("gene regulatory relations"))) or ("acute respiratory testing"))*.