What surface was the città di caltanissetta played on?
CREATE TABLE table_name_22 (surface VARCHAR, tournament VARCHAR)
SELECT surface FROM table_name_22 WHERE tournament = "città di caltanissetta"
### Context: CREATE TABLE table_name_22 (surface VARCHAR, tournament VARCHAR) ### Question: What surface was the città di caltanissetta played on? ### Answer: SELECT surface FROM table_name_22 WHERE tournament = "città di caltanissetta"