Perhaps you should try some spelling variations:
networks synthesis » networks systems, nets synthesis
network synthesis » network systems
health assurance » health reassurance, health insurance, health assistance
health science » health sciences

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