Perhaps you should try some spelling variations:
"_ optimisation algorithm" » "_ optimization algorithms", "_ estimation algorithm", "_ estimation algorithms", "_ optimization algorithm"
"risk approximation algorithms" » "time approximation algorithms", "_ approximation algorithms", "one approximation algorithms"
"_ optimize algorithm" » "_ optimized algorithm", "_ optimized algorithms", "_ optimizer algorithms", "_ optimise algorithm"

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: (("risk approximation algorithms") or ((("_ optimize algorithm") or ("_ optimisation algorithm"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("risk approximation algorithms") OR ((("_ optimize algorithm") OR ("_ optimisation algorithm")))).
• Removing quotes may allow a broader search: (( risk approximation algorithms ) or ((( _ optimize algorithm ) or ( _ optimisation algorithm )))).
• Adding a wildcard symbol may retrieve word variants: (("risk approximation algorithms") or ((("_ optimize algorithm") or ("_ optimisation algorithm"))))*.