Perhaps you should try some spelling variations:
"mathematics optimization" » "materials optimization"
"material optimization" » "numerical optimization", "criteria optimization", "combinatorial optimization"
"models optimization" » "model optimization", "modeling optimization"

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 ("mathematical optimization"))) OR ((("models optimization") OR ("material optimization")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"mathematics optimization\") OR (\"mathematical optimization\"))) or (((\"models optimization\") or (\"material optimization\"))))".
• Removing quotes may allow a broader search: (((( mathematics optimization ) OR ( mathematical optimization ))) or ((( models optimization ) or ( material optimization )))).
• Adding a wildcard symbol may retrieve word variants: (((("mathematics optimization") OR ("mathematical optimization"))) or ((("models optimization") or ("material optimization"))))*.