Perhaps you should try some spelling variations:
"image processing algorithm" » "image modeling algorithm" (Expand Search), "image routing algorithm" (Expand Search), "image tracking algorithm" (Expand Search)
"element tree algorithms" » "element three algorithms" (Expand Search), "element art algorithms" (Expand Search), "element two algorithms" (Expand Search), "element ree algorithms" (Expand Search), "element te algorithms" (Expand Search), "element ore algorithms" (Expand Search)
"presence data algorithm" » "presence data algorithms" (Expand Search), "presence update algorithm" (Expand Search), "presence atlas algorithm" (Expand Search), "prevalence data 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: (((("element tree algorithms") OR ("presence data algorithm"))) OR ("image processing algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"element tree algorithms\") OR (\"presence data algorithm\"))) OR (\"image processing algorithm\"))".
• Removing quotes may allow a broader search: (((( element tree algorithms ) OR ( presence data algorithm ))) OR ( image processing algorithm )).
• Adding a wildcard symbol may retrieve word variants: (((("element tree algorithms") OR ("presence data algorithm"))) OR ("image processing algorithm"))*.