user: Question: What surface was played on with a score of 6–4, 6–3 and on 4 May 1992?
Columns: ['Date', 'Tournament', 'Surface', 'Partnering', 'Opponent in the final', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['4 May 1992', 'Waregem , Belgium', 'Clay', 'Manon Bollegraf', 'Elena Bryukhovets Petra Langrová', '6–4, 6–3']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Score" = '6–4, 6–3' AND "Date" = '4 May 1992';