Perhaps you should try some spelling variations:
decreases sperm » decreased sperm (Expand search), decreases serum (Expand search), decreasing sperm (Expand search)
decrease faster » decrease after (Expand search), decrease further (Expand search), decreased after (Expand search)
faster decrease » rate decrease (Expand search)
sperm decrease » term decrease (Expand search), speed decrease (Expand search), speed decreases (Expand search)
in decreases » in decreased (Expand search), and decreases (Expand search), ivm decreases (Expand search)
decrease or » decrease of (Expand search), decrease pro (Expand search), decrease toc (Expand search)
or object » art object (Expand search), an object (Expand search), en object (Expand search)

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: (( decrease in decreases sperm decrease ) OR ( decrease faster decrease OR object ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease in decreases sperm decrease ) OR ( decrease faster decrease or object ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease in decreases sperm decrease ) OR ( decrease faster decrease or object ))*.