Perhaps you should try some spelling variations:
rca » arca, rcac, rcga
orcac » oarcac, orcacc, orcgac, orcad, rcac, dorcac, orcadc, arcac
orca » oarca, orcac, orcga, dorca, orcad, arca
aorca » aoarca, aorcac, aorcga, adorca, aorcad, aarca, arca, aorta, dorca
oarcad » oaarcad, oarcacd, oarcgad, orcad
roca » rocca, rocha, boca

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

• Performing a fuzzy search may retrieve terms with similar spellings: modified (((((rca or roca) or ohca) or (orcac or orca)) or aorca) or oarcad) estimation algorithm~.
• If you are trying to use Boolean operators, they must be ALL CAPS: modified (((((rca OR roca) OR ohca) OR (orcac OR orca)) OR aorca) OR oarcad) estimation algorithm.
• Adding a wildcard symbol may retrieve word variants: modified (((((rca or roca) or ohca) or (orcac or orca)) or aorca) or oarcad) estimation algorithm*.