Perhaps you should try some spelling variations:
"inverse discrete index" » "inverse distance index", "versus discrete index", "inverse discrete lindley", "inverse discrete input", "inverse discrete ideal"
"dense discrete index" » "dense discrete lindley", "dense discrete input", "dense discrete ideal"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"inverse discrete index\") OR (\"dense discrete index\"))*".
• Removing quotes may allow a broader search: (( inverse discrete index ) OR ( dense discrete index ))*.