Talvez deva tentar algumas variações de ortografia:
center survey » cluster survey (Expandir a Pesquisa)
survey cause » survey caused (Expandir a Pesquisa), survey course (Expandir a Pesquisa), survey use (Expandir a Pesquisa)
spinal nerve » retinal nerve (Expandir a Pesquisa)
serve case » nerve case (Expandir a Pesquisa), service case (Expandir a Pesquisa), nerve cases (Expandir a Pesquisa)
cause des » cause de (Expandir a Pesquisa), cause dna (Expandir a Pesquisa)
nerve can » merve can (Expandir a Pesquisa), nerve cat (Expandir a Pesquisa), nerve cn (Expandir a Pesquisa)
a center » a century (Expandir a Pesquisa)
i spinal » _ spinal (Expandir a Pesquisa), a spinal (Expandir a Pesquisa), i spiral (Expandir a Pesquisa)
j kengen » m kengen (Expandir a Pesquisa), j kennon (Expandir a Pesquisa), j kenyon (Expandir a Pesquisa)
case dis » case disc (Expandir a Pesquisa), case di (Expandir a Pesquisa), case does (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.

• Performing a fuzzy search may retrieve terms with similar spellings: (((( a center survey cause des ) or ( i spinal nerve can dcs ))) or ( j kengen serve case dis ))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (((( a center survey cause des ) OR ( i spinal nerve can dcs ))) OR ( j kengen serve case dis ))*.