Perhaps you should try some spelling variations:
decreases sperm » decreased sperm (Expand search), decreases serum (Expand search), decreasing sperm (Expand search)
sperm decrease » term decrease (Expand search), speed decrease (Expand search), speed decreases (Expand search)
the decreases » the decrease (Expand search), the decreased (Expand search), use decreases (Expand search)
in professor » in professors (Expand search), and professor (Expand search), ai professor (Expand search)
decrease the » decreases the (Expand search), decrease of (Expand search)
decrease at » decrease akt (Expand search), decrease and (Expand search), decrease of (Expand search)
at decrease » rate decrease (Expand search), that decrease (Expand search), and decrease (Expand search)

You may be able to get more results by adjusting your search query.

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