Perhaps you should try some spelling variations:
disease incidence » diseases incident
network synthesis » network systems
health incidence » death incidence, health incident, health science
networks system » network system, network systems, networked systems
system report » system reform, system support, system reforms
guide network » guided network, side network, wide network
health guide » health guido, earth guide, health grid

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 incidence) OR (disease incidence)) networks system report ) OR ( health guide network synthesis report )).
• Adding a wildcard symbol may retrieve word variants: (( ((health incidence) or (disease incidence)) networks system report ) or ( health guide network synthesis report ))*.