Talvez deva tentar algumas variações de ortografia:
central nerve » ventral nerve (Expandir a Pesquisa), central nervous (Expandir a Pesquisa), central neural (Expandir a Pesquisa)
nerve system » nervous system (Expandir a Pesquisa), drive system (Expandir a Pesquisa)
high central » high contrast (Expandir a Pesquisa), high spectral (Expandir a Pesquisa), both central (Expandir a Pesquisa)
benign nerve » benign nevi (Expandir a Pesquisa), benign neck (Expandir a Pesquisa), benign beale (Expandir a Pesquisa)
cent nerve » bent nerve (Expandir a Pesquisa), recent nerve (Expandir a Pesquisa), crest nerve (Expandir a Pesquisa)
system dis » system dias (Expandir a Pesquisa), system dcs (Expandir a Pesquisa), system dds (Expandir a Pesquisa)
a benign » _ benign (Expandir a Pesquisa)
nerve a » nerve _ (Expandir a Pesquisa)
i cent » i cento (Expandir a Pesquisa), ai cent (Expandir a Pesquisa), ii cent (Expandir a Pesquisa)
a dcs » a dcsk (Expandir a Pesquisa), a dos (Expandir a Pesquisa), a des (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": "(((( i cent nerve system dis ) OR ( high central nerve a dcs ))) OR ( a benign nerve system dis ))~".
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( i cent nerve system dis ) OR ( high central nerve a dcs ))) OR ( a benign nerve system dis ))*.