Perhaps you should try some spelling variations:
"use modelling mathematical" » "use processing mathematical", "use scheduling mathematical", "use making mathematical", "user modelling mathematical"
"use modern mathematical" » "use modern mathematics", "use london mathematical", "pre modern mathematical", "use model mathematical", "use models mathematical"
"index models mathematics" » "index model mathematics", "index models mathematical", "index modern mathematics", "induced models mathematics"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("index models mathematics") or ((("use modelling mathematical") OR ("use modern mathematical"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("index models mathematics") OR ((("use modelling mathematical") OR ("use modern mathematical")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"index models mathematics\") or (((\"use modelling mathematical\") OR (\"use modern mathematical\"))))".
• Removing quotes may allow a broader search: (( index models mathematics ) or ((( use modelling mathematical ) OR ( use modern mathematical )))).
• Adding a wildcard symbol may retrieve word variants: (("index models mathematics") or ((("use modelling mathematical") OR ("use modern mathematical"))))*.