r>
          Volume 3, Sorting and Searching,<br>
          Second Edition,<br>
          Addison Wesley, 1998,<br>
          ISBN: 0201896850,<br>
          LC: QA76.6.K64.
        </li>
        <li>
          Albert Nijenhuis, Herbert Wilf,<br>
          Combinatorial Algorithms for Computers and Calculators,<br>
          Academic Press, 1978,<br>
          ISBN: 0-12-519260-6,<br>
          LC: QA164.N54.
        </li>
      </ol>
    </p>

    <h3 align = "center">
      Source Code:
    </h3>

    <p>