Provide more links.

diff --git a/include/deal.II/grid/manifold_lib.h b/include/deal.II/grid/manifold_lib.h
index e105719f3fca8f313940a10462b6cb1b50083c8a..892b2fe2c2a5d1d0e30d7135e0a4962f06865644 100644 (file)
--- a/include/deal.II/grid/manifold_lib.h
+++ b/include/deal.II/grid/manifold_lib.h
@@ -47,6 +47,10 @@ DEAL_II_NAMESPACE_OPEN
  * system. This point is a singular point of the coordinate transformation,
  * and there taking averages does not make any sense.
  *
+ * This class is used in step-1 and step-2 to describe the boundaries
+ * of circles. Its use is also discussed in the results section of
+ * step-6.
+ *
  * @ingroup manifold
  *
  * @author Luca Heltai, 2014