Talvez deva tentar algumas variações de ortografia:
recurrent nerve » recurrent neural (Expandir a Pesquisa)
direct neural » direct neuronal (Expandir a Pesquisa), direct peroral (Expandir a Pesquisa), direct oral (Expandir a Pesquisa)
j recurrent » _ recurrent (Expandir a Pesquisa), a recurrent (Expandir a Pesquisa), 1 recurrent (Expandir a Pesquisa)
used direct » use direct (Expandir a Pesquisa), pulsed direct (Expandir a Pesquisa), used directly (Expandir a Pesquisa)
neural nas » neural na (Expandir a Pesquisa), neural nar (Expandir a Pesquisa), neural nets (Expandir a Pesquisa)
nerve pen » nerve pet (Expandir a Pesquisa), nerve aen (Expandir a Pesquisa), nerve pain (Expandir a Pesquisa)
pen due » en due (Expandir a Pesquisa), men due (Expandir a Pesquisa), pen dye (Expandir a Pesquisa)
nas dis » nas duas (Expandir a Pesquisa), nas dfps (Expandir a Pesquisa), nas adcs (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 recurrent nerve pen due ) OR ( used direct neural nas dis ))~.
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( j recurrent nerve pen due ) or ( used direct neural nas dis ))*.