Perhaps you should try some spelling variations:
decrease optimum » discrete optimum (Expand search), decrease sodium (Expand search), reverse optimum (Expand search)
optimum training » optimum planting (Expand search), optimum spacing (Expand search)
decrease further » increase further (Expand search), disease further (Expand search), decrease the (Expand search)
further decrease » further increase (Expand search), faster decrease (Expand search), the decrease (Expand search)
during decrease » during increased (Expand search), during depressed (Expand search), during disease (Expand search)
decrease to » decreased to (Expand search), decrease toc (Expand search), decrease the (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: "(( increase during decrease optimum training ) OR ( decrease further decrease to decrease ))~".
• Adding a wildcard symbol may retrieve word variants: (( increase during decrease optimum training ) OR ( decrease further decrease to decrease ))*.