private function getRegistrationGroupElement()
    {
        if (isset($this->isbnSplit[0]) === false or $this->isbnSplit[0] === '978') {
            $this->range("0000000", "5999999", 1, 1);
            $this->range("6000000", "6499999", 3, 1);
            $this->range("6500000", "6999999", 0, 1);
            $this->range("7000000", "7999999", 1, 1);
            $this->range("8000000", "9499999", 2, 1);
            $this->range("9500000", "9899999", 3, 1);
            $this->range("9900000", "9989999", 4, 1);
            $this->range("9990000", "9999999", 5, 1);
        }

        if (isset($this->isbnSplit[0]) === true and $this->isbnSplit[0] === '979') {
            $this->range("0000000", "0999999", 0, 1);
            $this->range("1000000", "1199999", 2, 1);
            $this->range("1200000", "9999999", 0, 1);
        }

        return (isset($this->isbnSplit[1]));
    }