Talvez deva tentar algumas variações de ortografia:
levels rather » cells rather (Expandir a Pesquisa)
nurses levels » nurses level (Expandir a Pesquisa), nurse level (Expandir a Pesquisa), sources levels (Expandir a Pesquisa)
mode theory » model theory (Expandir a Pesquisa), modern theory (Expandir a Pesquisa), models theory (Expandir a Pesquisa)
live rather » liver rather (Expandir a Pesquisa), naive rather (Expandir a Pesquisa), live farther (Expandir a Pesquisa)
drug nurses » drug nurse (Expandir a Pesquisa), during nurses (Expandir a Pesquisa), young nurses (Expandir a Pesquisa)
drug does » drug doses (Expandir a Pesquisa), drugs does (Expandir a Pesquisa), drug dose (Expandir a Pesquisa)
does mode » does more (Expandir a Pesquisa), does money (Expandir a Pesquisa), does male (Expandir a Pesquisa)
does live » does liver (Expandir a Pesquisa), does olive (Expandir a Pesquisa), does life (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: (( drug does mode theory ) or ((( drug does live rather ) or ( drug nurses levels rather ))))~.
• Se usar operadores Booleanos, por favor insira-os com letras MAIÚSCULAS: (( drug does mode theory ) OR ((( drug does live rather ) OR ( drug nurses levels rather )))).
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( drug does mode theory ) or ((( drug does live rather ) or ( drug nurses levels rather ))))*.