Perhaps you should try some spelling variations:
"level coding algorithm" » "level cosine algorithm" (Expand Search), "level colony algorithm" (Expand Search), "level scheduling algorithm" (Expand Search)
"fragment based algorithm" » "agent based algorithm" (Expand Search), "gradient based algorithm" (Expand Search)
"elemental mapping algorithm" » "elementary mapping algorithm" (Expand Search), "elements mapping algorithm" (Expand Search), "element mapping 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: (("fragment based algorithm") OR ((("elemental mapping algorithm") OR ("level coding algorithm"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"fragment based algorithm\") OR (((\"elemental mapping algorithm\") OR (\"level coding algorithm\"))))".
• Removing quotes may allow a broader search: (( fragment based algorithm ) OR ((( elemental mapping algorithm ) OR ( level coding algorithm )))).
• Adding a wildcard symbol may retrieve word variants: (("fragment based algorithm") OR ((("elemental mapping algorithm") OR ("level coding algorithm"))))*.