Talvez deva tentar algumas variações de ortografia:
ventral nerve » femoral nerve (Expandir a Pesquisa)
nerve system » nervous system (Expandir a Pesquisa), reserve system (Expandir a Pesquisa), drive system (Expandir a Pesquisa)
benign nerve » benign nevi (Expandir a Pesquisa), benign neck (Expandir a Pesquisa), benign nevus (Expandir a Pesquisa)
crest nerve » treat nerve (Expandir a Pesquisa), crest derived (Expandir a Pesquisa), current nerve (Expandir a Pesquisa)
system dis » system dias (Expandir a Pesquisa), system di (Expandir a Pesquisa), system das (Expandir a Pesquisa)
a ventral » a ventura (Expandir a Pesquisa)
nerve can » merve can (Expandir a Pesquisa), nerve cat (Expandir a Pesquisa), nerve cn (Expandir a Pesquisa)
j benign » j benigno (Expandir a Pesquisa), i benign (Expandir a Pesquisa), ii benign (Expandir a Pesquisa)
can dcs » can tdcs (Expandir a Pesquisa), can dce (Expandir a Pesquisa), can dags (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": "(((( _ crest nerve system dis ) OR ( a ventral nerve can dcs ))) OR ( j benign nerve system dis ))~".
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( _ crest nerve system dis ) OR ( a ventral nerve can dcs ))) OR ( j benign nerve system dis ))*.