Table: stwc_race_results
Columns: round
race
circuit
date
event
winning_driver
winning_team

Question: What is the circuit for the ADAC großer preis der tourenwagen race?
SQL: SELECT "circuit" FROM stwc_race_results WHERE "race" = 'adac großer preis der tourenwagen'

Question: What is the date that Fabrizio Giovanardi Christian Abt won?
SQL: SELECT "date" FROM stwc_race_results WHERE "winning_driver" = 'fabrizio giovanardi christian abt'