Perhaps you should try some spelling variations:
complex context » complex contact (Expand Search), complex concepts (Expand Search), complex control (Expand Search)
mers complex » phers complex (Expand Search), qrs complex (Expand Search), rs complex (Expand Search)
carlos nova » carlos novoa (Expand Search), carlos nava (Expand Search), carlos noa (Expand Search)
kno carlos » cano carlos (Expand Search), nino carlos (Expand Search), pino carlos (Expand Search)
7.5 nacl » 3.5 nacl (Expand Search), 0.9 nacl (Expand Search)
nacl kno » nacl nano (Expand Search), nacl en (Expand Search), nacl kcl (Expand Search)
e combs » sex combs (Expand Search)
combs c » combs _ (Expand Search)
5 mers » 5 meters (Expand Search)
c new » a new (Expand Search), _ new (Expand Search), c neu (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.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( j e combs c new ) OR ((( 5 mers complex context new ) OR ( 7.5 nacl kno carlos nova ))))~.
• Adding a wildcard symbol may retrieve word variants: (( j e combs c new ) or ((( 5 mers complex context new ) or ( 7.5 nacl kno carlos nova ))))*.