Talvez deva tentar algumas variações de ortografia:
research systems » research synthesis (Expandir a Pesquisa)
mental research » dental research (Expandir a Pesquisa), central research (Expandir a Pesquisa), neonatal research (Expandir a Pesquisa)
benzo nerve » benign nerve (Expandir a Pesquisa)
systems das » systems dss (Expandir a Pesquisa), systems dds (Expandir a Pesquisa), systems data (Expandir a Pesquisa)
bent nerve » absent nerve (Expandir a Pesquisa), mental nerve (Expandir a Pesquisa), dental nerve (Expandir a Pesquisa)
nerve cat » nerve can (Expandir a Pesquisa), nerve ct (Expandir a Pesquisa), nerve cut (Expandir a Pesquisa)
cat diet » cat diets (Expandir a Pesquisa), fat diet (Expandir a Pesquisa), eat diet (Expandir a Pesquisa)
j mental » j mengual (Expandir a Pesquisa), j mena (Expandir a Pesquisa), j mehta (Expandir a Pesquisa)
i benzo » i benito (Expandir a Pesquisa)
nerve c » nerve cn (Expandir a Pesquisa), nerve co (Expandir a Pesquisa), nerve ct (Expandir a Pesquisa)
j bent » j benet (Expandir a Pesquisa), j bento (Expandir a Pesquisa), j bena (Expandir a Pesquisa)
c dias » c diaz (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 bent nerve cat diet ) OR ( i benzo nerve c dias ))) OR ( j mental research systems das ))~".
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j bent nerve cat diet ) OR ( i benzo nerve c dias ))) OR ( j mental research systems das ))*.