ak.html">a FORTRAN90 version</a> and
      <a href = "../../m_src/chrpak/chrpak.html">a MATLAB version</a>. 
    </p>

    <h3 align = "center">
      Reference:
    </h3>

    <p>
      <ol>
        <li>
          Carl Branden, John Tooze,<br>
          Introduction to Protein Structure,<br>
          Second Edition,<br>
          Garland Publishing, 1999,<br>
          ISBN: 0815323050,<br>
          LC: QP551.B7635.
        </li>
        <li>
          Paul Bratley, Bennett Fox, Linus Schrage,<br>
      