From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Thu, 16 Mar 2023 17:56:53 +0000 (-0600)
Subject: Add a link to the documentation.
X-Git-Tag: v9.5.0-rc1~452^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d1daef28a94620e844080d44f76f98e21a548a6c;p=dealii.git

Add a link to the documentation.
---

diff --git a/doc/doxygen/headers/vector_valued.h b/doc/doxygen/headers/vector_valued.h
index fd1ad5a735..33c4387f53 100644
--- a/doc/doxygen/headers/vector_valued.h
+++ b/doc/doxygen/headers/vector_valued.h
@@ -85,7 +85,8 @@
  * Here, <b>D</b> denotes the symmetric gradient defined by
  * $\mathbf Du = \tfrac12 (\nabla \mathbf u + (\nabla \mathbf u)^T)$
  * and the colon indicates double contraction of two tensors of rank 2
- * (the Frobenius inner product). This bilinear form looks indeed very
+ * (the [Frobenius inner product](https://en.wikipedia.org/wiki/Frobenius_inner_product)).
+ * This bilinear form looks indeed very
  * much like the bilinear form of the Poisson problem in step-3. The
  * only differences are
  * <ol>