user: Question: What was the start source that ended on 4 May?
Columns: ['Name', 'Country', 'Loan Club', 'Started', 'Ended', 'Start Source', 'End Source']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Clapham', 'ENG', 'Wolverhampton Wanderers', '20 August', '20 November', 'BBC Sport', 'Leeds United']
SQL:

assistant: SELECT "Start Source" FROM "Table" WHERE "Ended" = '4 May';