Talvez deva tentar algumas variações de ortografia:
research systems » research synthesis (Expandir a Pesquisa)
amon research » among research (Expandir a Pesquisa), moon research (Expandir a Pesquisa), amongst research (Expandir a Pesquisa)
spinal nerve » retinal nerve (Expandir a Pesquisa)
center nurse » center nurses (Expandir a Pesquisa), letter nurse (Expandir a Pesquisa), cancer nurse (Expandir a Pesquisa)
systems de » systems do (Expandir a Pesquisa), systems mems (Expandir a Pesquisa), systems data (Expandir a Pesquisa)
nurse cat » nurse can (Expandir a Pesquisa), nurse ca (Expandir a Pesquisa), nurse cadet (Expandir a Pesquisa)
j center » j centner (Expandir a Pesquisa), j centeno (Expandir a Pesquisa), j cestero (Expandir a Pesquisa)
i spinal » a spinal (Expandir a Pesquisa), i spiral (Expandir a Pesquisa), iii spinal (Expandir a Pesquisa)
cat dis » cat did (Expandir a Pesquisa), cat diets (Expandir a Pesquisa), cat diet (Expandir a Pesquisa)
nerve c » nerve cn (Expandir a Pesquisa), nerve _ (Expandir a Pesquisa), nerve a (Expandir a Pesquisa)
c dias » c diaz (Expandir a Pesquisa)
j amon » j amor (Expandir a Pesquisa)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

Pode obter mais resultados ajustando a pesquisa.

• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (((( j center nurse cat dis ) OR ( i spinal nerve c dias ))) OR ( j amon research systems de ))~.
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (((( j center nurse cat dis ) or ( i spinal nerve c dias ))) or ( j amon research systems de ))*.