Talvez deva tentar algumas variações de ortografia:
research systems » research synthesis (Expandir a Pesquisa)
medina research » media research (Expandir a Pesquisa), medica research (Expandir a Pesquisa), medical research (Expandir a Pesquisa)
systems dis » systems disk (Expandir a Pesquisa), systems tdis (Expandir a Pesquisa), systems dss (Expandir a Pesquisa)
cent nerve » bent nerve (Expandir a Pesquisa), recent nerve (Expandir a Pesquisa), crest nerve (Expandir a Pesquisa)
nerve van » nerve vas (Expandir a Pesquisa), herve van (Expandir a Pesquisa), nerve a (Expandir a Pesquisa)
i retinal » ii retinal (Expandir a Pesquisa), hi retinal (Expandir a Pesquisa), a retinal (Expandir a Pesquisa)
nerve cn » nerve can (Expandir a Pesquisa), nerve c (Expandir a Pesquisa), nerve cat (Expandir a Pesquisa)
j medina » j mejia (Expandir a Pesquisa)
van dis » van die (Expandir a Pesquisa), van diest (Expandir a Pesquisa), van dijk (Expandir a Pesquisa)
a cent » a cena (Expandir a Pesquisa), a cenp (Expandir a Pesquisa), a center (Expandir a Pesquisa)
cn dos » con dos (Expandir a Pesquisa), cen dos (Expandir a Pesquisa), dcn 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: (((( a cent nerve van dis ) or ( i retinal nerve cn dos ))) or ( j medina research systems dis ))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (((( a cent nerve van dis ) OR ( i retinal nerve cn dos ))) OR ( j medina research systems dis )).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( a cent nerve van dis ) or ( i retinal nerve cn dos ))) or ( j medina research systems dis ))*.