Perhaps you should try some spelling variations:
"head impedances network synthesis report" » "head impedance network synthesis report", "head impedance networks synthesis report", "head impededance network synthesis report", "load impedance network synthesis report", "end impedance network synthesis report"
"health sciences network systems report" » "health services network systems report", "earth sciences network systems report", "health sciences network system report", "health sciences network systems support", "health sciences network systems recent"

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 sciences network systems report") OR ("head impedances network synthesis report")).
• Removing quotes may allow a broader search: (( health sciences network systems report ) or ( head impedances network synthesis report )).
• Adding a wildcard symbol may retrieve word variants: (("health sciences network systems report") or ("head impedances network synthesis report"))*.