Perhaps you should try some spelling variations:
complex trial » complex atrial (Expand Search), complex tibial (Expand Search), complex tropical (Expand Search)
carlos nara » carlos lara (Expand Search), carlos nava (Expand Search), carlos jara (Expand Search)
combs john » coombs john (Expand Search), combes john (Expand Search), coombes john (Expand Search)
john neetu » john reetu (Expand Search), john neena (Expand Search), jain neetu (Expand Search)
trial nimh » trial nit (Expand Search)
nao carlos » sao carlos (Expand Search), cao carlos (Expand Search), rao carlos (Expand Search)
7.5 nacl » 3.5 nacl (Expand Search), 0.9 nacl (Expand Search)
nacl nao » nacl nano (Expand Search), nacl naoh (Expand Search), nacl na (Expand Search)
l combs » e combs (Expand Search), _ combs (Expand Search), l comps (Expand Search)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( j l combs john neetu ) or ((( 5 a complex trial nimh ) or ( 7.5 nacl nao carlos nara ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( j l combs john neetu ) OR ((( 5 a complex trial nimh ) OR ( 7.5 nacl nao carlos nara )))).
• Adding a wildcard symbol may retrieve word variants: (( j l combs john neetu ) or ((( 5 a complex trial nimh ) or ( 7.5 nacl nao carlos nara ))))*.