https://arstechnica.com/cars/2018/01/delta-sends-the-last-us-passenger-747-into-retirement/
origin - http://www.pipiscrew.com/2018/01/as-of-today-no-us-airlines-operate-the-mighty-boeing-747/ as-of-today-no-us-airlines-operate-the-mighty-boeing-747
https://arstechnica.com/cars/2018/01/delta-sends-the-last-us-passenger-747-into-retirement/
origin - http://www.pipiscrew.com/2018/01/as-of-today-no-us-airlines-operate-the-mighty-boeing-747/ as-of-today-no-us-airlines-operate-the-mighty-boeing-747