user: Question: Whose Runner-up has a Semifinalist of Guillermo Pérez-Roldán Andrea Gaudenzi?
Columns: ['Week of', 'Tournament', 'Champions', 'Runners-up', 'Semifinalists']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['13 September', 'Bucharest , Romania $500,000', 'Goran Ivanišević 6-2 7-6(5)', 'Andrei Cherkasov', 'Guillermo Pérez-Roldán Andrea Gaudenzi']
SQL:

assistant: SELECT "Runners-up" FROM "Table" WHERE "Semifinalists" = 'Guillermo Pérez-Roldán Andrea Gaudenzi';