Perhaps you should try some spelling variations:
decreased learning » decreases weaning (Expand search), increases learning (Expand search), decreased during (Expand search)
learning object » learning objects (Expand search)
decrease costs » decreasing costs (Expand search), decreases post (Expand search), disease costs (Expand search)
costs decrease » loss decrease (Expand search), cells decrease (Expand search), cost increase (Expand search)
decrease not » decrease of (Expand search), decrease akt (Expand search), decrease at (Expand search)
not decrease » to decrease (Expand search), not increase (Expand search), and decrease (Expand search)
in decreased » is decreased (Expand search), in deceased (Expand search), and decreased (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 NOT decrease costs decrease ) OR ( decrease in decreased learning object ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease not decrease costs decrease ) OR ( decrease in decreased learning object ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease not decrease costs decrease ) OR ( decrease in decreased learning object ))*.