Perhaps you should try some spelling variations:
feedstocks synthesis » feedstocks systems, feedstocks analysis
feedback synthesis » feedback systems
health evidence » health science
science shock » science stock, science short, science shops
science shop » science short, science school, science should
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 evidence ((network synthesis) OR (network systems)) report ) OR ( health ((science shock) OR (science shop)) synthesis report ))) OR ( health guide ((feedstocks synthesis) OR (feedback synthesis)) report )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( health evidence ((network synthesis) or (network systems)) report ) or ( health ((science shock) OR (science shop)) synthesis report ))) or ( health guide ((feedstocks synthesis) or (feedback synthesis)) report ))".
• Adding a wildcard symbol may retrieve word variants: (((( health evidence ((network synthesis) or (network systems)) report ) or ( health ((science shock) OR (science shop)) synthesis report ))) or ( health guide ((feedstocks synthesis) or (feedback synthesis)) report ))*.