Perhaps you should try some spelling variations:
"query processing algorithm" » "query processing algorithms" (Expand Search), "text processing algorithm" (Expand Search)
"element based algorithm" » "event based algorithm" (Expand Search)
"element tree algorithms" » "element three algorithms" (Expand Search), "element free algorithms" (Expand Search)

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: "((((\"element based algorithm\") OR (\"element tree algorithms\"))) OR (\"query processing algorithm\"))~".
• Removing quotes may allow a broader search: (((( element based algorithm ) OR ( element tree algorithms ))) OR ( query processing algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (((("element based algorithm") OR ("element tree algorithms"))) OR ("query processing algorithm"))*.