Perhaps you should try some spelling variations:
"index models mathematics" » "index model mathematics", "index models mathematical", "index modeling mathematics", "induced models mathematics"
"index model mathematical" » "index models mathematical", "index modern mathematical", "index modeling mathematical"
"india modern mathematics" » "india model mathematics", "indonesia modern mathematics", "dunia modern 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 ("india modern mathematics"))) OR ("index model mathematical"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"index models mathematics\") OR (\"india modern mathematics\"))) OR (\"index model mathematical\"))".
• Removing quotes may allow a broader search: (((( index models mathematics ) OR ( india modern mathematics ))) OR ( index model mathematical )).
• Adding a wildcard symbol may retrieve word variants: (((("index models mathematics") OR ("india modern mathematics"))) OR ("index model mathematical"))*.