78,<br>
          ISBN: 0677041500,<br>
          LC: QA404.5 C44.
        </li>
        <li>
          William Cody,<br>
          Rational Chebyshev Approximations for the Error Function,<br>
          Mathematics of Computation,<br>
          Volume 23, Number 107, July 1969, pages 631-638.
        </li>
        <li>
          Robert Corless, Gaston Gonnet, David Hare, David Jeffrey, 
          Donald Knuth,<br>
          On the Lambert W Function,<br>
          Advances in Computational Mathematics,<br>