Perhaps you should try some spelling variations:
"implement retinex algorithm" » "implement cosine algorithm" (Expand Search), "implemented retinex algorithm" (Expand Search), "implementing retinex algorithm" (Expand Search)
"level coding algorithm" » "level cosine algorithm" (Expand Search), "level colony algorithm" (Expand Search), "level scheduling algorithm" (Expand Search)
"elements fe algorithms" » "elements _ algorithms" (Expand Search), "elements rd algorithm" (Expand Search), "elementi per algorithms" (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: (((("implement retinex algorithm") OR ("elements fe algorithms"))) OR ("level coding algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"implement retinex algorithm\") OR (\"elements fe algorithms\"))) OR (\"level coding algorithm\"))".
• Removing quotes may allow a broader search: (((( implement retinex algorithm ) OR ( elements fe algorithms ))) OR ( level coding algorithm )).
• Adding a wildcard symbol may retrieve word variants: (((("implement retinex algorithm") OR ("elements fe algorithms"))) OR ("level coding algorithm"))*.