Perhaps you should try some spelling variations:
"online sand research instruments" » "online sand research instrument", "online sand research instrumentation", "online sand research environments", "online sands research instruments", "online rand research instruments", "online land research instruments", "online sind research instruments", "online sale research instruments", "online sao research instruments"
"online hand research comments" » "online hand research commons", "online hand research contents", "online hand research commentary", "online rand research comments", "online land research comments", "online brand research comments", "online band research comments", "online handel research comments"
"online hand research students" » "online hand research studies", "online hand research study", "online hand research studying", "online rand research students", "online land research students", "online brand research students", "online band research students", "online handel research students"
"online sand research students" » "online sand research studies", "online sand research study", "online sand research studying", "online sands research students", "online rand research students", "online land research students", "online sind research students", "online sale research students", "online sao research students"
"online hand research agent" » "online hand research agenda", "online hand research agency", "online hand search agent", "online rand research agent", "online land research agent", "online brand research agent", "online band research agent", "online handel research agent"

Try widening your search to All Fields.

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: (("online hand research comments") OR ((("online hand research agent") OR ((("online hand research students") OR ((("online sand research students") OR ("online sand research instruments")))))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"online hand research comments\") or (((\"online hand research agent\") or (((\"online hand research students\") or (((\"online sand research students\") OR (\"online sand research instruments\"))))))))".
• Removing quotes may allow a broader search: (( online hand research comments ) or ((( online hand research agent ) or ((( online hand research students ) or ((( online sand research students ) OR ( online sand research instruments )))))))).
• Adding a wildcard symbol may retrieve word variants: (("online hand research comments") or ((("online hand research agent") or ((("online hand research students") or ((("online sand research students") OR ("online sand research instruments"))))))))*.