Talvez deva tentar algumas variações de ortografia:
research systems » research synthesis (Expandir a Pesquisa)
mehta research » meta research (Expandir a Pesquisa), beta research (Expandir a Pesquisa), eha research (Expandir a Pesquisa)
current nerve » recurrent nerve (Expandir a Pesquisa), current curve (Expandir a Pesquisa), recurrent nerves (Expandir a Pesquisa)
cancer nerve » cancer serves (Expandir a Pesquisa), cancer needle (Expandir a Pesquisa), cancer nested (Expandir a Pesquisa)
systems de » systems do (Expandir a Pesquisa), systems mems (Expandir a Pesquisa), systems data (Expandir a Pesquisa)
nerve can » nerve canal (Expandir a Pesquisa), nerve case (Expandir a Pesquisa), nerve a (Expandir a Pesquisa)
j cancer » j canter (Expandir a Pesquisa), j cantero (Expandir a Pesquisa), j candel (Expandir a Pesquisa)
can dis » can disc (Expandir a Pesquisa), van dis (Expandir a Pesquisa), can die (Expandir a Pesquisa)
nerve c » nerve cn (Expandir a Pesquisa), nerve _ (Expandir a Pesquisa), nerve a (Expandir a Pesquisa)
c dos » e dos (Expandir a Pesquisa), a dos (Expandir a Pesquisa)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

Pode obter mais resultados ajustando a pesquisa.

• "As palabras AND, OR e NOT podem gerar pesquisas incorrectas; tente utilizar aspas": "(((( j cancer nerve can dis ) OR ( i current nerve c dos ))) OR ( a mehta research systems de ))~".
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j cancer nerve can dis ) OR ( i current nerve c dos ))) OR ( a mehta research systems de ))*.