Talvez deva tentar algumas variações de ortografia:
threat levers » threat levels (Expandir a Pesquisa), threat level (Expandir a Pesquisa), threat severe (Expandir a Pesquisa)
nerve cause » nerve caused (Expandir a Pesquisa), nerve case (Expandir a Pesquisa), nerve course (Expandir a Pesquisa)
levers cat » levels can (Expandir a Pesquisa), levers a (Expandir a Pesquisa)
mena nerve » mental nerve (Expandir a Pesquisa), renal nerve (Expandir a Pesquisa), menan herve (Expandir a Pesquisa)
cause does » causes does (Expandir a Pesquisa), cause des (Expandir a Pesquisa), pause does (Expandir a Pesquisa)
bent nerve » absent nerve (Expandir a Pesquisa), mental nerve (Expandir a Pesquisa), dental nerve (Expandir a Pesquisa)
j threat » al threat (Expandir a Pesquisa)
cat dis » cat did (Expandir a Pesquisa), cat diets (Expandir a Pesquisa), cat diet (Expandir a Pesquisa)
nerve a » nerve _ (Expandir a Pesquisa)
j mena » j medina (Expandir a Pesquisa)
l bent » l benth (Expandir a Pesquisa), l bengt (Expandir a Pesquisa), l bento (Expandir a Pesquisa)
a dis » a dos (Expandir a Pesquisa), a des (Expandir a Pesquisa), a dia (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 threat levers cat dis ) or ((( j mena nerve cause does ) or ( l bent nerve a dis ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( j threat levers cat dis ) OR ((( j mena nerve cause does ) OR ( l bent nerve a dis )))).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( j threat levers cat dis ) or ((( j mena nerve cause does ) or ( l bent nerve a dis ))))*.