Perhaps you should try some spelling variations:
"modified time approximation algorithm" » "modified time approximation algorithms", "modified one approximation algorithm", "modified _ approximation algorithm", "modified bi1 approximation algorithm", "modified male approximation algorithm"
"modified staffing optimisation algorithm" » "modified staffing optimization algorithms", "modified staffing estimation algorithm", "modified staffing estimation algorithms", "modified staffing optimization algorithm", "modified static optimization algorithm", "modified caging optimisation algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified time approximation algorithm") OR ("modified staffing optimisation algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified time approximation algorithm\") OR (\"modified staffing optimisation algorithm\"))".
• Removing quotes may allow a broader search: (( modified time approximation algorithm ) OR ( modified staffing optimisation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified time approximation algorithm") OR ("modified staffing optimisation algorithm"))*.