Perhaps you should try some spelling variations:
"modified allocation optimization algorithms" » "modified allocation optimisation algorithm", "modified allocation estimation algorithms", "modified allocation estimation algorithm", "modified location optimization algorithms"
"modified invasive approximation algorithms" » "modified passive approximation algorithms"

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

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