/p>

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

    <p>
      <ol>
        <li>
          Fred Fritsch, RE Shafer, WP Crowley,<br>
          Algorithm 443:
          Solution of the Transcendental Equation W*exp(W)=X,<br>
          Communications of the ACM,<br>
          Volume 16, Number 1, February 1973, pages 123-124.
        </li>
        <li>
          Andrew Barry, S. J. Barry, Patricia Culligan-Hensley,<br>
          Algorithm 743: WAPR - A Fortran routine for calculating real 
          