Perhaps you should try some spelling variations:
improv\ » improve\ (Expand Search), improved\ (Expand Search)
improveed\ » improveeed\ (Expand Search), improvedeed\ (Expand Search), improved\ (Expand Search), improve\ (Expand Search)
improvedde » improveedde (Expand Search), improvededde (Expand Search), improved (Expand Search)
improveed » improveeed (Expand Search), improvedeed (Expand Search), improved (Expand Search), improve (Expand Search)
improvede » improveede (Expand Search), improvedede (Expand Search), improved (Expand Search), improve (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\ theatre (((improv\ OR improveed\) OR improvedde ) OR improveed )) OR (\ theatre improvede ))~".
• Adding a wildcard symbol may retrieve word variants: ((\ theatre (((improv\ OR improveed\) OR improvedde ) OR improveed )) OR (\ theatre improvede ))*.