Talvez deva tentar algumas variações de ortografia:
research systems » research synthesis (Expandir a Pesquisa)
mental research » dental research (Expandir a Pesquisa), central research (Expandir a Pesquisa), neonatal research (Expandir a Pesquisa)
cancer nerve » cancer serves (Expandir a Pesquisa), cancer nurse (Expandir a Pesquisa), cancer nurses (Expandir a Pesquisa)
systems das » systems adas (Expandir a Pesquisa), systems dss (Expandir a Pesquisa), systems dds (Expandir a Pesquisa)
bent nerve » absent nerve (Expandir a Pesquisa), mental nerve (Expandir a Pesquisa), dental nerve (Expandir a Pesquisa)
nerve _at » nerve cat (Expandir a Pesquisa), nerve a (Expandir a Pesquisa), nerve can (Expandir a Pesquisa)
j cancer » j canter (Expandir a Pesquisa), j cantero (Expandir a Pesquisa), j cancela (Expandir a Pesquisa)
j mental » j mengual (Expandir a Pesquisa), j mehta (Expandir a Pesquisa), j mena (Expandir a Pesquisa)
_at dis » rat disc (Expandir a Pesquisa)
i bent » i benth (Expandir a Pesquisa), i benet (Expandir a Pesquisa), i bento (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 cancer nerve _at dis ) or ( i bent nerve _ dis ))) or ( j mental research systems das ))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (((( j cancer nerve _at dis ) OR ( i bent nerve _ dis ))) OR ( j mental research systems das )).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j cancer nerve _at dis ) or ( i bent nerve _ dis ))) or ( j mental research systems das ))*.