Talvez deva tentar algumas variações de ortografia:
knopf carlos » prof carlos (Expandir a Pesquisa)
cobalt trieu » cobalt trial (Expandir a Pesquisa), cobalt tris (Expandir a Pesquisa), cobalt traces (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), combes john (Expandir a Pesquisa), coombes john (Expandir a Pesquisa)
trieu ngoc » tieu ngoc (Expandir a Pesquisa), trieu ngoa (Expandir a Pesquisa), trinh ngoc (Expandir a Pesquisa)
nacl knopf » nacl kno (Expandir a Pesquisa)
john new » john agnew (Expandir a Pesquisa), john neil (Expandir a Pesquisa), john noel (Expandir a Pesquisa)
_ ethane » _ ethanol (Expandir a Pesquisa), _ ethno (Expandir a Pesquisa)
7.5 nacl » 3.5 nacl (Expandir a Pesquisa), 0.9 nacl (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 _ combs john new ) or ((( _ ethane cobalt trieu ngoc ) or ( 7.5 nacl knopf carlos nora ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( j _ combs john new ) OR ((( _ ethane cobalt trieu ngoc ) OR ( 7.5 nacl knopf carlos nora )))).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( j _ combs john new ) or ((( _ ethane cobalt trieu ngoc ) or ( 7.5 nacl knopf carlos nora ))))*.