fixes reference in 6.4 to subsection 5.3.3

Author: albertobottopoala

higher-order/higher-order-burgers.tex

@@ -9,7 +9,7 @@ \section{WENO methods, nonlinear equations, and flux-splitting}
   \label{eq:scalar_conslaw}
   u_t + f(u)_x = 0
 \end{equation}
-the WENO method introduced in section~\ref{sec:ho-intro} above does not work,
+the WENO method introduced in subsection~\ref{sec:WENO} above does not work,
 as we have assumed the characteristic
 information travels in one direction only. We have also reconstructed the
 variable $q$ and from that constructed the ``flux'' which we feed into the