update documentation, part X

doc/doxygen/references.bib

@@ -474,6 +474,18 @@ @article {GuermondPopov2016
        DOI = {10.1137/16M1074291},
 }
 
+@article {GuermondPopov2016b,
+    AUTHOR = {Guermond, Jean-Luc and Popov, Bojan},
+     TITLE = {Fast estimation of the maximum wave speed in the Riemann problem for the Euler equations},
+   JOURNAL = {J. Comput. Phys.},
+  FJOURNAL = {Journal of Computational Physics},
+    VOLUME = {321},
+      YEAR = {2016},
+     PAGES = {908--926},
+      ISSN = {0021-9991},
+       DOI = {10.1016/j.jcp.2016.05.054},
+}
+
 @article {GuermondEtAl2018,
     AUTHOR = {Guermond, Jean-Luc and Nazarov, Murtazo and Popov, Bojan and
               Tomas, Ignacio},
@@ -543,6 +555,15 @@ @book{Rainald2008
 year = {2008},
 }
 
+@book {Toro2009,
+  AUTHOR = {Eleuterio F. Toro},
+  PUBLISHER = {Springer-Verlag, Berlin, Heidelberg},
+  ISBN = {9783540252023},
+  TITLE ={Riemann Solvers and Numerical Methods for Fluid Dynamics},
+  doi = {10.1007/b79761},
+  year = {2009}
+}
+
 % ------------------------------------
 % Step 71
 % ------------------------------------

examples/step-69/doc/intro.dox

@@ -12,8 +12,7 @@ high-performance implementation of a second-order accurate scheme that uses
 <i>convex limiting</i> techniques, and strong stability-preserving (SSP)
 time integration, see @cite GuermondEtAl2018.
 
-@todo Add zenodo link
-
+@dealiiTutorialDOI{10.5281/zenodo.3634929,https://zenodo.org/badge/DOI/10.5281/zenodo.3634929.svg}
 
 <h1>Introduction</h1>
 
@@ -40,8 +39,6 @@ tutorial step to be a good starting point (in particular with respect to
 the programming techniques) before jumping into full research codes such as
 the second-order scheme @cite GuermondEtAl2018.
 
-@todo Add link to repository and project of the second order code.
-
 
 <a name="eulerequations"></a>
 <h3>Euler's equations of gas dynamics</h3>

examples/step-69/doc/tooltip

@@ -0,0 +1 @@
+Hyperbolic conservation laws: a first-order guaranteed maximum wavespeed method for the compressible Euler equations