user: Question: What is Surface, when Opponents, when Final is "Gigi Fernández Robin White"?
Columns: ['Outcome', 'Year', 'Championship', 'Surface', 'Partner', 'Opponents in final', 'Score in final']
Types: ['text', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Runner-up', 1988.0, 'US Open', 'Hard', 'Jill Hetherington', 'Gigi Fernández Robin White', '6–4, 6–1']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Opponents in final" = 'Gigi Fernández Robin White';