Perhaps you should try some spelling variations:
better research » between research (Expand Search), weather research (Expand Search), water research (Expand Search)
dental nerve » mental nerve (Expand Search), ventral nerve (Expand Search), central nerve (Expand Search)
system des » system der (Expand Search), system de (Expand Search), system design (Expand Search)
nerve cyst » nerve cystic (Expand Search), nerve case (Expand Search), nerve cat (Expand Search)
system di » system de (Expand Search), system d (Expand Search), system dias (Expand Search)
j better » _ better (Expand Search), a better (Expand Search), 3 better (Expand Search)
j dental » j dent (Expand Search), j delta (Expand Search), j deal (Expand Search)
cyst dis » cyst due (Expand Search), cyst d (Expand Search), cyst dna (Expand Search)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( j better research ((system di) or (system des)) ) or ( j dental nerve cyst dis ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( j better research ((system di) OR (system des)) ) OR ( j dental nerve cyst dis )).
• Adding a wildcard symbol may retrieve word variants: (( j better research ((system di) or (system des)) ) or ( j dental nerve cyst dis ))*.