Perhaps you should try some spelling variations:
"mathematics optimization" » "mathematical optimization", "materials optimization"
"material optimization" » "numerical optimization", "criteria optimization", "mathematical optimization"
"automatic estimation" » "automatic optimization", "automatic extraction", "automatic evaluation"

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: (((("mathematics optimization") OR ("automatic estimation"))) OR ("material optimization")).
• Removing quotes may allow a broader search: (((( mathematics optimization ) or ( automatic estimation ))) or ( material optimization )).
• Adding a wildcard symbol may retrieve word variants: (((("mathematics optimization") or ("automatic estimation"))) or ("material optimization"))*.