Talvez deva tentar algumas variações de ortografia:
central research » dental research (Expandir a Pesquisa), general research (Expandir a Pesquisa), centred research (Expandir a Pesquisa)
research systems » research synthesis (Expandir a Pesquisa)
retina nerve » retinal nerve (Expandir a Pesquisa), retina novel (Expandir a Pesquisa)
systems das » systems dss (Expandir a Pesquisa), systems dds (Expandir a Pesquisa), systems data (Expandir a Pesquisa)
bent nerve » absent nerve (Expandir a Pesquisa), mental nerve (Expandir a Pesquisa), dental nerve (Expandir a Pesquisa)
nerve can » nerve canal (Expandir a Pesquisa), nerve case (Expandir a Pesquisa), nerve a (Expandir a Pesquisa)
j central » 1hfj central (Expandir a Pesquisa)
j retina » j reina (Expandir a Pesquisa), j retana (Expandir a Pesquisa), j reino (Expandir a Pesquisa)
can die » can diet (Expandir a Pesquisa), van die (Expandir a Pesquisa), aan die (Expandir a Pesquisa)
nerve c » nerve cn (Expandir a Pesquisa), nerve co (Expandir a Pesquisa), nerve ct (Expandir a Pesquisa)
i bent » i benth (Expandir a Pesquisa), i benet (Expandir a Pesquisa), i bento (Expandir a Pesquisa)
c dis » c dias (Expandir a Pesquisa), c disc (Expandir a Pesquisa), c dos (Expandir a Pesquisa)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

Pode obter mais resultados ajustando a pesquisa.

• Performing a fuzzy search may retrieve terms with similar spellings: (((( j retina nerve can die ) or ( i bent nerve c dis ))) or ( j central research systems das ))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (((( j retina nerve can die ) OR ( i bent nerve c dis ))) OR ( j central research systems das )).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j retina nerve can die ) or ( i bent nerve c dis ))) or ( j central research systems das ))*.