Perhaps you should try some spelling variations:
network synthesis » network systems
substance network » distance network, substrate network, resistance network
evidence network » guidance network, dence network, incidence networks
science network » sciences network, science networks, science work
system report » system reform, system support, system recent
health guide » health guido, health grid, health side
earth guide » search guide, bath guide, earth tide

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: (( health ((evidence network) OR (science network)) system report ) OR ((( health substance network synthesis report ) OR ( ((health guide) OR (earth guide)) network synthesis report )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( health ((evidence network) or (science network)) system report ) or ((( health substance network synthesis report ) or ( ((health guide) OR (earth guide)) network synthesis report ))))".
• Adding a wildcard symbol may retrieve word variants: (( health ((evidence network) or (science network)) system report ) or ((( health substance network synthesis report ) or ( ((health guide) OR (earth guide)) network synthesis report ))))*.