Perhaps you should try some spelling variations:
metil complex » metal complex (Expand Search), metals complex (Expand Search), met complex (Expand Search)
complex trace » complex traces (Expand Search), complexed trace (Expand Search), complete trace (Expand Search)
kno carlos » cano carlos (Expand Search), nino carlos (Expand Search), pino carlos (Expand Search)
carlos now » carlos noe (Expand Search), carlos noa (Expand Search), carlos novo (Expand Search)
comps con » compost con (Expand Search), comps los (Expand Search)
trace ngo » trace n (Expand Search), trace co (Expand Search), trace ni (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)
l comps » m comps (Expand Search)
con new » icon new (Expand Search), con nee (Expand Search), con net (Expand Search)
5 metil » 5 methyl (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 l comps con new ) OR ((( 5 metil complex trace ngo ) OR ( 7.5 nacl kno carlos now ))))~.
• Adding a wildcard symbol may retrieve word variants: (( j l comps con new ) or ((( 5 metil complex trace ngo ) or ( 7.5 nacl kno carlos now ))))*.