Perhaps you should try some spelling variations:
networks synthesis » networks systems, nets synthesis
network synthesis » network systems
health assistance » health substance, cash assistance
evidence network » science network, guidance network, dence network
health assurance » health reassurance, health insurance, health insurances
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 assurance) OR (health assistance)) networks synthesis report )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( health evidence network synthesis report ) or ( ((health assurance) OR (health assistance)) networks synthesis report ))".
• Adding a wildcard symbol may retrieve word variants: (( health evidence network synthesis report ) or ( ((health assurance) OR (health assistance)) networks synthesis report ))*.