Talvez deva tentar algumas variações de ortografia:
burden company » burden compared (Expandir a Pesquisa), burden coping (Expandir a Pesquisa), burden common (Expandir a Pesquisa)
rat compared » rats compared (Expandir a Pesquisa), rate compared (Expandir a Pesquisa), fat compared (Expandir a Pesquisa)
compared can » compared case (Expandir a Pesquisa), compared a (Expandir a Pesquisa), compared law (Expandir a Pesquisa)
company a » company _ (Expandir a Pesquisa)
art come » art como (Expandir a Pesquisa), art came (Expandir a Pesquisa), art code (Expandir a Pesquisa)
come can » comes can (Expandir a Pesquisa), home can (Expandir a Pesquisa), cme can (Expandir a Pesquisa)
can non » dan non (Expandir a Pesquisa), than non (Expandir a Pesquisa)
a netw » a neto (Expandir a Pesquisa), a neta (Expandir a Pesquisa), a netb (Expandir a Pesquisa)
j rat » j rath (Expandir a Pesquisa), _ rat (Expandir a Pesquisa), a rat (Expandir a Pesquisa)
j art » j arts (Expandir a Pesquisa), j arlt (Expandir a Pesquisa), _ art (Expandir a Pesquisa)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

Pode obter mais resultados ajustando a pesquisa.

• "As palabras AND, OR e NOT podem gerar pesquisas incorrectas; tente utilizar aspas": "(((( j rat compared can new ) OR ( j art come can non ))) OR ( _ burden company a netw ))~".
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j rat compared can new ) OR ( j art come can non ))) OR ( _ burden company a netw ))*.