Perhaps you should try some spelling variations:
"elemental xrd algorithm" » "elemental rd algorithm" (Expand Search), "elementary xrd algorithm" (Expand Search), "elements xrd algorithm" (Expand Search), "elementsal xrd algorithm" (Expand Search)
"elemental rf algorithm" » "elemental rd algorithm" (Expand Search), "elemental _ algorithms" (Expand Search), "elementary rf algorithm" (Expand Search), "elements rf algorithm" (Expand Search), "elementsal rf algorithm" (Expand Search)
"element mapping algorithm" » "elements 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: (((("elemental xrd algorithm") OR ("elemental rf algorithm"))) OR ("element mapping algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"elemental xrd algorithm\") OR (\"elemental rf algorithm\"))) OR (\"element mapping algorithm\"))".
• Removing quotes may allow a broader search: (((( elemental xrd algorithm ) OR ( elemental rf algorithm ))) OR ( element mapping algorithm )).
• Adding a wildcard symbol may retrieve word variants: (((("elemental xrd algorithm") OR ("elemental rf algorithm"))) OR ("element mapping algorithm"))*.