user: Question: Who was the TO winning team when the TU winning team was Joe Richardson? 
Columns: ['Rnd', 'Circuit', 'GTO Winning Team', 'GTU Winning Team', 'TO Winning Team', 'TU Winning Team', 'Results']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Virginia', '#57 Corvette', '#59 Brumos Porsche - Audi', '#21 Javelin', '#71 Opel', 'Results']
SQL:

assistant: SELECT "TO Winning Team" FROM "Table" WHERE "TU Winning Team" = 'Joe Richardson';