Talvez deva tentar algumas variações de ortografia:
does develop » boys develop (Expandir a Pesquisa), loss develop (Expandir a Pesquisa), does developing (Expandir a Pesquisa)
develop them » develop type (Expandir a Pesquisa)
level theory » model theory (Expandir a Pesquisa)
uses level » use level (Expandir a Pesquisa), user level (Expandir a Pesquisa), nurses level (Expandir a Pesquisa)
dose level » dose levels (Expandir a Pesquisa), noise level (Expandir a Pesquisa), dose live (Expandir a Pesquisa)
level ther » level rather (Expandir a Pesquisa), levels other (Expandir a Pesquisa), level taper (Expandir a Pesquisa)
drug does » drug doses (Expandir a Pesquisa), drugs does (Expandir a Pesquisa), drug de (Expandir a Pesquisa)
drug uses » drug users (Expandir a Pesquisa), drug use (Expandir a Pesquisa), drug user (Expandir a Pesquisa)
drug dose » drug dosage (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: (( drug does develop them ) OR ((( drug uses level theory ) OR ( drug dose level ther ))))~.
• Se adicionar um carácter universal pode recuperar variações da palavra pesquisada: (( drug does develop them ) or ((( drug uses level theory ) or ( drug dose level ther ))))*.