public function getSortedCellList()
    {
        $sortKeys = array();
        foreach ($this->getCellList() as $coord) {
            sscanf($coord, '%[A-Z]%d', $column, $row);
            $sortKeys[sprintf('%09d%3s', $row, $column)] = $coord;
        }
        ksort($sortKeys);

        return array_values($sortKeys);
    }