unction written in another programming language.
    </p>

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

    <p>
      <ul>
        <li>
          The gfortran team,<br>
          Using GNU Fortran,<br>
          The Free Software Foundation, 2010,<br>
          <a href = "../../pdf/gfortran.pdf">gfortran.pdf</a>.
        </li>
        <li>
          Fritz Keinert,<br>
          Mathematics Department,<br>
          Iowa State University,<br>
          Calling FORTRAN Subroutines from Fortran, C and