Perhaps you should try some spelling variations:
network system » network systems, networked systems
earth distance » search distance, path distance, garch distance
nets synthesis » net synthesis, dots synthesis, its synthesis
dence network » dense network, defence network, dense networks
distance nets » distance sets, distance new, distance lists
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 system support ) OR ( earth distance nets synthesis report )).
• Adding a wildcard symbol may retrieve word variants: (( health dence network system support ) or ( earth distance nets synthesis report ))*.