user: Question: Where did the player with a Transfer type, a Summer Transfer window, and ended before 2013 move from?
Columns: ['Nat.', 'Name', 'Moving from', 'Type', 'Transfer window', 'Ends', 'Transfer fee', 'Source']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['DNK', 'D. Jensen', 'Youth system', 'Promoted', 'Summer', 2011.0, 'Youth system', 'FCK.dk']
SQL:

assistant: SELECT "Moving from" FROM "Table" WHERE "Type" = 'Transfer' AND "Transfer window" = 'Summer' AND "Ends" < 2013.0;