Reference book directly in step-55.

diff --git a/examples/step-55/doc/intro.dox b/examples/step-55/doc/intro.dox
index 5f70c1433cdee1379a1d0863765d9f1b1529177f..08f31a2d57bc66e11e4a3bf152b99a94fa81dac0 100644 (file)
--- a/examples/step-55/doc/intro.dox
+++ b/examples/step-55/doc/intro.dox
@@ -131,8 +131,8 @@ We will use approximations of the inverse operations in $P^{-1}$ that are
 (nearly) independent of $h$. In this situation, one can again show, that the
 eigenvalues are independent of $h$. For the Krylov method we choose MINRES,
 which is attractive for the analysis (iteration count is proven to be
-independent of $h$, see the remainder of the chapter 6.2.1 in the book
-mentioned above), great from the computational standpoint (simpler and cheaper
+independent of $h$, see the remainder of the chapter 6.2.1 in @cite elman2005),
+great from the computational standpoint (simpler and cheaper
 than GMRES for example), and applicable (matrix and preconditioner are
 symmetric).