Perhaps you should try some spelling variations:
network synthesis » network systems
substance network » substrate network, resistance network, distance networks
evidence network » science network, guidance network, dence network
distance network » distance networks, resistance network, disease network
health evidence » health science

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