Perhaps you should try some spelling variations:
"mathematical optimisation" » "mathematics optimization", "mathematical applications", "mathematical formulation"
"mathematical simulation" » "mathematical formulation", "mathematical foundation", "mathematical induction"

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