user: Question: Who was the Cover model in the issue in which the Interview subject was Joan Collins?
Columns: ['Date', 'Cover model', 'Centerfold model', 'Interview subject', 'Pictorials']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1-84', 'no model pictured', 'Penny Baker', 'Dan Rather', 'Mariel Hemingway in Star 80']
SQL:

assistant: SELECT "Cover model" FROM "Table" WHERE "Interview subject" = 'Joan Collins';