Perhaps you should try some spelling variations:
"spatial clustering algorithm" » "data clustering algorithm" (Expand Search)
"element based algorithm" » "event based algorithm" (Expand Search)
"data backing algorithm" » "data banking algorithm" (Expand Search), "data lacking algorithm" (Expand Search), "data packing algorithm" (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("spatial clustering algorithm") OR ("data backing algorithm"))) OR ("element based algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"spatial clustering algorithm\") OR (\"data backing algorithm\"))) OR (\"element based algorithm\"))".
• Removing quotes may allow a broader search: (((( spatial clustering algorithm ) OR ( data backing algorithm ))) OR ( element based algorithm )).
• Adding a wildcard symbol may retrieve word variants: (((("spatial clustering algorithm") OR ("data backing algorithm"))) OR ("element based algorithm"))*.