Perhaps you should try some spelling variations:
recursions » recessions, recursos, recursives, recursoss, excursions
excursions » exclusions
reversions » perversions, revisions, reversing, versions, aversions, diversions
recursion » recursive, recursos, excursion
reversion » version, aversion, diversion
recession » regression

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((recursions OR excursions) or reversions) or ((recursion or reversion) or recession))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((recursions OR excursions) OR reversions) OR ((recursion OR reversion) OR recession)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((recursions OR excursions) or reversions) or ((recursion or reversion) or recession))".
• Adding a wildcard symbol may retrieve word variants: (((recursions OR excursions) or reversions) or ((recursion or reversion) or recession))*.