e
        Gaussian beams generated during 3D field calculations.</li>
    </ul>
    <p style="font-family: monospace;">The various programs for
      computing fields (GROUP III) are only needed for PLOTSHD, or for
      special user programs (e.g. ambiguity surfaces).</p>
    <p style="font-family: monospace;">The following extensions are used
      with these programs:</p>
    <ul style="font-family: monospace;">
      <li>&nbsp; .F90&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The
        Fortran90/95 sour