Perhaps you should try some spelling variations:
complex tien » complex times (Expand Search), complex than (Expand Search), complex time (Expand Search)
den complex » denv complex (Expand Search), een complex (Expand Search), dense complex (Expand Search)
nabr carlos » jair carlos (Expand Search), mar carlos (Expand Search), aybar carlos (Expand Search)
combs john » coombs john (Expand Search), combes john (Expand Search), coombes john (Expand Search)
carlos nor » carlos noa (Expand Search), carlos noe (Expand Search), carlos nobre (Expand Search)
tien ngoc » tran ngoc (Expand Search), tuan ngoc (Expand Search), diep ngoc (Expand Search)
nacl nabr » nacl kbr (Expand Search), nacl nano (Expand Search), nacl naoh (Expand Search)
john new » john agnew (Expand Search), john neil (Expand Search), john n (Expand Search)
l combs » e combs (Expand Search), _ combs (Expand Search), l comps (Expand Search)
5 den » _ den (Expand Search), i den (Expand Search), m den (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 combs john new ) OR ((( 5 den complex tien ngoc ) OR ( 3.5 nacl nabr carlos nor ))))~.
• Adding a wildcard symbol may retrieve word variants: (( j l combs john new ) or ((( 5 den complex tien ngoc ) or ( 3.5 nacl nabr carlos nor ))))*.