Perhaps you should try some spelling variations:
networks synthesis » networks systems, nets synthesis
network synthesis » network systems
evidence network » science network, dence network, incidence networks
health incidence » death incidence, health incident, path incidence
guidance network » guide network, finance network, guided network
health impedance » health importance, health temperance, head impedance
health guidance » health finance, health substance
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 network synthesis report ) OR ( ((health incidence) OR (health science)) networks synthesis report ))) OR ((( health guidance network synthesis report ) OR ( health impedance network synthesis report )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( health evidence network synthesis report ) or ( ((health incidence) or (health science)) networks synthesis report ))) or ((( health guidance network synthesis report ) OR ( health impedance network synthesis report ))))".
• Adding a wildcard symbol may retrieve word variants: (((( health evidence network synthesis report ) or ( ((health incidence) or (health science)) networks synthesis report ))) or ((( health guidance network synthesis report ) OR ( health impedance network synthesis report ))))*.