Perhaps you should try some spelling variations:
"springer science aging mexico" » "stronger science aging mexico", "river science aging mexico", "springer springe aging mexico", "springer science imaging mexico", "springer science among mexico", "springer science again mexico", "springer science aging mexican", "springer science facing mexico", "springer science making mexico"
"springer science using lexicon" » "stronger science using lexicon", "river science using lexicon", "springer springe using lexicon", "springer science using lexical", "springer science using silicon"

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: (("springer science aging mexico") OR ("springer science using lexicon")).
• Removing quotes may allow a broader search: (( springer science aging mexico ) or ( springer science using lexicon )).
• Adding a wildcard symbol may retrieve word variants: (("springer science aging mexico") or ("springer science using lexicon"))*.