Talvez deva tentar algumas variações de ortografia:
knopf carlos » prof carlos (Expandir a Pesquisa)
complex tran » complex trans (Expandir a Pesquisa), complex than (Expandir a Pesquisa), complex trait (Expandir a Pesquisa)
carlos nejar » carlos negrao (Expandir a Pesquisa), carlos nava (Expandir a Pesquisa)
copps john » coppin john (Expandir a Pesquisa), apps john (Expandir a Pesquisa), coles john (Expandir a Pesquisa)
23 several » _ several (Expandir a Pesquisa), a several (Expandir a Pesquisa), al several (Expandir a Pesquisa)
nacl knopf » nacl kno (Expandir a Pesquisa)
john noe » john noel (Expandir a Pesquisa), john noh (Expandir a Pesquisa), john noble (Expandir a Pesquisa)
7.5 nacl » 3.5 nacl (Expandir a Pesquisa), 0.9 nacl (Expandir a Pesquisa)
l copps » l copp (Expandir a Pesquisa), _ copps (Expandir a Pesquisa), l coppel (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 l copps john noe ) or ((( 23 several complex tran ngoc ) or ( 7.5 nacl knopf carlos nejar ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( j l copps john noe ) OR ((( 23 several complex tran ngoc ) OR ( 7.5 nacl knopf carlos nejar )))).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( j l copps john noe ) or ((( 23 several complex tran ngoc ) or ( 7.5 nacl knopf carlos nejar ))))*.