Perhaps you should try some spelling variations:
substance network » distance network, substrate network, resistance network
systems report » system report, systems support, systems recent
dence network » dense network, defence network, dense networks
health dence » health device, 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 dence network synthesis report ) OR ( health substance network systems report )).
• Adding a wildcard symbol may retrieve word variants: (( health dence network synthesis report ) or ( health substance network systems report ))*.