+##Example 41: Clamped Biharmonic
+
+
+This example demonstrates one way that MFEM can be used to solve PDEs with higher-order derivatives by using the $C^0$ interior penalty method by [Brenner and Sung](https://doi.org/10.1007/s10915-004-4135-7). The biharmonic equation with clamped boundary conditions,
+
+$$\nabla^4u=1 \text{ in } \Omega,$$
+$$u=0 \text{ and } \nabla u\cdot \hat{n}=0 \text{ on } \partial\Omega,$$
+
+is solved using $H^1$-conforming finite elements. Development of custom domain and face integrators are shown. See the example code for a more detailed description of the method.
+
+_The example has a serial ([ex41.cpp](https://github.com/mfem/mfem/blob/master/examples/ex41.cpp))
+and a parallel ([ex41p.cpp](https://github.com/mfem/mfem/blob/master/examples/ex41p.cpp)) version.
+We recommend viewing Example 1 and Example 14 before viewing this example._
+