Perhaps you should try some spelling variations:
method complex » methods complex (Expand Search), method coupled (Expand Search), method complexity (Expand Search)
complex trans » complex traits (Expand Search), complex trait (Expand Search), complex tears (Expand Search)
knot carlos » knopf carlos (Expand Search), enout carlos (Expand Search), knotz carlo (Expand Search)
carlos jara » carlos lara (Expand Search), carlos carla (Expand Search), carlos juca (Expand Search)
trans ngo » tran ngo (Expand Search), trang ngo (Expand Search), trans tango (Expand Search)
nacl knot » nacl kno (Expand Search), nacl mno (Expand Search), nacl npt (Expand Search)
5 method » 5 methods (Expand Search), 5 methoxy (Expand Search), 5 methyl (Expand Search)
c.m bac » c.m bach (Expand Search), c.m bacon (Expand Search), c.m b.sc (Expand Search)
bac new » back new (Expand Search), bac ne (Expand Search), mac new (Expand Search)
l c.m » l com (Expand Search), l cam (Expand Search), _ c.m (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 c.m bac new ) or ((( 5 method complex trans ngo ) or ( 3.5 nacl knot carlos jara ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( j l c.m bac new ) OR ((( 5 method complex trans ngo ) OR ( 3.5 nacl knot carlos jara )))).
• Adding a wildcard symbol may retrieve word variants: (( j l c.m bac new ) or ((( 5 method complex trans ngo ) or ( 3.5 nacl knot carlos jara ))))*.