Talvez deva tentar algumas variações de ortografia:
ethical comparison » ethnical comparison (Expandir a Pesquisa), technical comparison (Expandir a Pesquisa), statical comparison (Expandir a Pesquisa)
nano carlos » cano carlos (Expandir a Pesquisa), nino carlos (Expandir a Pesquisa), nuno carlos (Expandir a Pesquisa)
carlos nora » carlos mora (Expandir a Pesquisa), carlos nara (Expandir a Pesquisa), carlos noa (Expandir a Pesquisa)
combs john » coombs john (Expandir a Pesquisa), coombes john (Expandir a Pesquisa), hobbs john (Expandir a Pesquisa)
5 ethical » _ ethical (Expandir a Pesquisa), 4 ethical (Expandir a Pesquisa), 7 ethical (Expandir a Pesquisa)
trial nic » trial nit (Expandir a Pesquisa), trial nimh (Expandir a Pesquisa), trial nihr (Expandir a Pesquisa)
nacl nano » nacl kno (Expandir a Pesquisa), nacl nabr (Expandir a Pesquisa)
john net » john new (Expandir a Pesquisa), john neetu (Expandir a Pesquisa), john asnet (Expandir a Pesquisa)
3.5 nacl » 0.9 nacl (Expandir a Pesquisa)
e combs » sex combs (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: (( j e combs john net ) or ((( 5 ethical comparison trial nic ) or ( 3.5 nacl nano carlos nora ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( j e combs john net ) OR ((( 5 ethical comparison trial nic ) OR ( 3.5 nacl nano carlos nora )))).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( j e combs john net ) or ((( 5 ethical comparison trial nic ) or ( 3.5 nacl nano carlos nora ))))*.