Perhaps you should try some spelling variations:
network synthesis » network systems
evidence network » science network, dence network, incidence networks
guidance network » guide network, finance network, guided network
health impedance » health importance, health temperance, head impedance
health guidance » health evidence, health finance

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) OR (guidance network)) synthesis report ) OR ((( ((health guidance) OR (health substance)) 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) OR (guidance network)) synthesis report ) or ((( ((health guidance) or (health substance)) network synthesis report ) or ( health impedance network synthesis report ))))".
• Adding a wildcard symbol may retrieve word variants: (( health ((evidence network) OR (guidance network)) synthesis report ) or ((( ((health guidance) or (health substance)) network synthesis report ) or ( health impedance network synthesis report ))))*.