Talvez deva tentar algumas variações de ortografia:
key comparison » survey comparison (Expandir a Pesquisa), assay comparison (Expandir a Pesquisa)
comparison law » comparison low (Expandir a Pesquisa), comparison land (Expandir a Pesquisa), comparison a (Expandir a Pesquisa)
rat compare » rat compared (Expandir a Pesquisa), rate compare (Expandir a Pesquisa), rats compare (Expandir a Pesquisa)
compr can » comp can (Expandir a Pesquisa), computer can (Expandir a Pesquisa), compared can (Expandir a Pesquisa)
compare a » compare _ (Expandir a Pesquisa)
can ngoc » van ngoc (Expandir a Pesquisa), tran ngoc (Expandir a Pesquisa), phan ngoc (Expandir a Pesquisa)
law now » laws now (Expandir a Pesquisa), law new (Expandir a Pesquisa), law non (Expandir a Pesquisa)
j key » _ key (Expandir a Pesquisa), a key (Expandir a Pesquisa), j kay (Expandir a Pesquisa)
j rat » j rath (Expandir a Pesquisa), _ rat (Expandir a Pesquisa), a rat (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: (( 2 (nat OR natl) compr can ngoc ) or ((( j key comparison law now ) or ( j rat compare a new ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( 2 (nat OR natl) compr can ngoc ) OR ((( j key comparison law now ) OR ( j rat compare a new )))).
• "As palabras AND, OR e NOT podem gerar pesquisas incorrectas; tente utilizar aspas": "(( 2 (nat OR natl) compr can ngoc ) or ((( j key comparison law now ) or ( j rat compare a new ))))".
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( 2 (nat OR natl) compr can ngoc ) or ((( j key comparison law now ) or ( j rat compare a new ))))*.