31379395simple systemPT2026-03-30 20:42:21UF31379396German systemNDUF31379397Meyer systemNDUF31379398old systemNDUF31379399ordinary systemNDUF31379400system, GermanNDUF31379401system, MeyerNDUF31379402system, oldNDUF31379403system, ordinaryNDUF31379404system, simpleNDBT31349321keyworkPT