Perhaps you should try some spelling variations:
health importance » health insurance
health impedance » health temperance, head impedance, health imperative
systems report » system report, systems support, systems recent
dence network » dense network, defence network, dense networks
health dence » health device, health evidence, health science
grid network » grid networks, hybrid network, world network
health grid » health guide, health guido, health gis

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