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)
decrease to » decreased to (Expand search), decrease toc (Expand search), decrease the (Expand search)
decrease il » decreased il (Expand search), decrease in (Expand search), decrease hiv (Expand search)
il subject » ill subject (Expand search), soil subject (Expand search), all subject (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 to decrease AND decrease ) OR ( decreases sperm decrease il subject ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease to decrease AND decrease ) OR ( decreases sperm decrease il subject ))*.