Perhaps you should try some spelling variations:
22stability theory » stability theory, instability theory, testability theory
bistability theory » stability theory, instability theory, testability theory
disability theory » viability theory, instability theory, stability theory

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

• If you are trying to use Boolean operators, they must be ALL CAPS: %((22stability theory) OR (((bistability theory) OR (disability theory))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((22stability theory) or (((bistability theory) OR (disability theory))))%22".
• Adding a wildcard symbol may retrieve word variants: %((22stability theory) or (((bistability theory) OR (disability theory))))%22*.