SELECT g2.START, g2.END, g2.CUSTOMER, g2.GAMBDEN, g1.START, g1.END, g1.CUSTOMER, g1.GAMBDEN FROM GamblingInstance g1, GamblingInstance g2 WHERE g1.CUSTOMER = g2.CUSTOMER AND g2.START BETWEEN g1.START AND g1.END AND NOT(g1.START = g2.START);