Talvez deva tentar algumas variações de ortografia:
research systems » research synthesis (Expandir a Pesquisa)
beta research » meta research (Expandir a Pesquisa), data research (Expandir a Pesquisa), sea research (Expandir a Pesquisa)
prevent nerve » prevents nerve (Expandir a Pesquisa), prevent neural (Expandir a Pesquisa), prevent anergy (Expandir a Pesquisa)
center nerve » cancer nerve (Expandir a Pesquisa), center nurse (Expandir a Pesquisa), letter nerve (Expandir a Pesquisa)
systems de » systems do (Expandir a Pesquisa), systems mems (Expandir a Pesquisa), systems data (Expandir a Pesquisa)
nerve can » merve can (Expandir a Pesquisa), nerve cat (Expandir a Pesquisa), nerve cn (Expandir a Pesquisa)
i prevent » i prevents (Expandir a Pesquisa), ii prevent (Expandir a Pesquisa), i present (Expandir a Pesquisa)
j center » j centner (Expandir a Pesquisa), j centeno (Expandir a Pesquisa), j cestero (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.

• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (((( j center nerve can dis ) OR ( i prevent nerve c dos ))) OR ( a beta research systems de ))~.
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j center nerve can dis ) or ( i prevent nerve c dos ))) or ( a beta research systems de ))*.