user: Question: What is Winner, when Date is "20 August"?
Columns: ['Circuit', 'City / State', 'Date', 'Winner', 'Team']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Mallala Motor Sport Park', 'Mallala , South Australia', '7 May', 'Mark McLaughlin', 'Elfin Sports Cars']
SQL:

assistant: SELECT "Winner" FROM "Table" WHERE "Date" = '20 August';