Talvez deva tentar algumas variações de ortografia:
negativity system » negative system (Expandir a Pesquisa), sensitivity system (Expandir a Pesquisa), activity system (Expandir a Pesquisa)
absent negativity » test negativity (Expandir a Pesquisa), false negativity (Expandir a Pesquisa), ana negativity (Expandir a Pesquisa)
crest nerve » treat nerve (Expandir a Pesquisa), crest derived (Expandir a Pesquisa), current nerve (Expandir a Pesquisa)
benet nerve » bent nerve (Expandir a Pesquisa), detect nerve (Expandir a Pesquisa), benign nerve (Expandir a Pesquisa)
system dis » system dias (Expandir a Pesquisa), system dcs (Expandir a Pesquisa), system di (Expandir a Pesquisa)
nerve cn » nerve can (Expandir a Pesquisa), nerve c (Expandir a Pesquisa), nerve cat (Expandir a Pesquisa)
_ absent » _ absence (Expandir a Pesquisa)
a crest » _ crest (Expandir a Pesquisa), a creusot (Expandir a Pesquisa), a crespo (Expandir a Pesquisa)
j benet » j bennett (Expandir a Pesquisa), j benito (Expandir a Pesquisa), j benesi (Expandir a Pesquisa)
cn due » con due (Expandir a Pesquisa), en due (Expandir a Pesquisa), chin due (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 crest nerve cn due ) or ((( j benet nerve cn due ) or ( _ absent negativity system dis ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( a crest nerve cn due ) OR ((( j benet nerve cn due ) OR ( _ absent negativity system dis )))).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( a crest nerve cn due ) or ((( j benet nerve cn due ) or ( _ absent negativity system dis ))))*.