Perhaps you should try some spelling variations:
trial compared » trial comparing (Expand Search), survival compared (Expand Search), trials comparing (Expand Search)
nacl compared » al compared (Expand Search), panel compared (Expand Search), gel compared (Expand Search)
compared can » compared law (Expand Search), companies can (Expand Search), compared _ (Expand Search)
than never » than ever (Expand Search)
compared a » compared _ (Expand Search)
comp than » camp than (Expand Search), comp trad (Expand Search), bump than (Expand Search)
la comp » la compr (Expand Search), la coma (Expand Search), la como (Expand Search)
5 nacl » _ nacl (Expand Search), 3 nacl (Expand Search), m nacl (Expand Search)
a now » a new (Expand Search), a non (Expand Search), _ now (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: (( y la comp than never ) OR ((( 5 nacl compared can new ) OR ( 3 trial compared a now ))))~.
• Adding a wildcard symbol may retrieve word variants: (( y la comp than never ) or ((( 5 nacl compared can new ) or ( 3 trial compared a now ))))*.