diff --git a/doc/doxygen/dumux.bib b/doc/doxygen/dumux.bib
index 7d0d3efe6dc28c669ba7e499ecbd4f9cc9b2a43a..b1fcbdf433fc28bffbc492d8d4a23ca7db36d5f8 100644
--- a/doc/doxygen/dumux.bib
+++ b/doc/doxygen/dumux.bib
@@ -2093,6 +2093,13 @@ author = {F. Fichot and F. Duval and N. Trégourès and C. Béchaud and M. Quint
   publisher = {Elsevier}
 }
 
+@inproceedings{Lomeland2005,
+  author = {Lomeland, F. and Ebeltoft, E. and Thomas, W.},
+  year = {2005},
+  title = {A New Versatile Relative Permeability Correlation},
+  journal = {Society of Core Analysis Conference Paper SCA2005-32}
+}
+
 @Article{Shomate1954,
   author    = {Shomate, C. Howard},
   title     = {A Method for Evaluating and Correlating Thermodynamic Data},
diff --git a/dumux/material/fluidmatrixinteractions/frictionlaws/frictionlaw.hh b/dumux/material/fluidmatrixinteractions/frictionlaws/frictionlaw.hh
index 047800fd84ae2ddc95ce4668706cdf9d12ea0209..652bc2f83128701d9d6da61e14fb3d8eff628e5a 100644
--- a/dumux/material/fluidmatrixinteractions/frictionlaws/frictionlaw.hh
+++ b/dumux/material/fluidmatrixinteractions/frictionlaws/frictionlaw.hh
@@ -22,8 +22,12 @@ namespace Dumux {
  * needed to calculate on the one hand the loss of momentum due to
  * bottom friction and on the other hand the bedload transport rate.
  *
- * A LET mobility model can be used to add an artificial water depth to
- * limit the friction for small water depths.
+ * A LET mobility model of Lomeland et al. 2005 \cite Lomeland2005 can be used to add an
+ * artificial water depth to limit the friction for small water depths.
+ *
+ * \note Instead of calculating the bed friction term \f$\mathbf{S_f}\f$
+ *       of the shallow water equations, the implemented friction laws
+ *       calculate the shear stress \f$\tau_{x}\f$ and \f$\tau_{y}\f$.
  */
 
 template <typename VolumeVariables >
diff --git a/dumux/material/fluidmatrixinteractions/frictionlaws/manning.hh b/dumux/material/fluidmatrixinteractions/frictionlaws/manning.hh
index 782d29f892853372b9bc8268338aa916b9eaef71..3a69df5c4ecdb4fbe44e844f2db87e18c1e0d80b 100644
--- a/dumux/material/fluidmatrixinteractions/frictionlaws/manning.hh
+++ b/dumux/material/fluidmatrixinteractions/frictionlaws/manning.hh
@@ -20,7 +20,15 @@ namespace Dumux {
  * ### Manning
  *
  * This friction law calculates the stress between the flowing fluid and the bottom,
- * which is called bottom shear stress, using the Manning friction law.
+ * which is called bottom shear stress, using the Manning friction law:
+ *
+ * \f$\tau_{x} = \frac{g}{(\frac{h^{1/6}}{n})^2} u \sqrt{u^2 + v^2}\f$ and
+ * \f$\tau_{y} = \frac{g}{(\frac{h^{1/6}}{n})^2} v \sqrt{u^2 + v^2}\f$
+ *
+ * with the gravity constant \f$\mathrm{g}\f$ in \f$\mathrm{[m/s^2]}\f$, the water depth
+ * \f$\mathrm{h}\f$ in \f$\mathrm{[m]}\f$ and the Manning friction coefficient
+ * \f$\mathrm{n}\f$ in \f$\mathrm{[s/m^{1/3}]}\f$.
+ *
  * The bottom shear stress is needed to calculate on the one hand the loss of
  * momentum due to bottom friction and on the other hand the bedload transport rate.
  *
diff --git a/dumux/material/fluidmatrixinteractions/frictionlaws/nikuradse.hh b/dumux/material/fluidmatrixinteractions/frictionlaws/nikuradse.hh
index 6dfe5146914b029544a336424462547828985ebc..2fdf42c971956aeec4b3e3c782f79db682053654 100644
--- a/dumux/material/fluidmatrixinteractions/frictionlaws/nikuradse.hh
+++ b/dumux/material/fluidmatrixinteractions/frictionlaws/nikuradse.hh
@@ -20,12 +20,21 @@ namespace Dumux {
  * ### Nikuradse
  *
  * This friction law calculates the stress between the flowing fluid and the bottom,
- * which is called bottom shear stress, using the Nikuradse friction law.
+ * which is called bottom shear stress, using the Nikuradse \cite Nikuradse1950 friction law
+ *
+ *\f$\tau_{x} = \frac{\kappa^2}{(ln\frac{12h}{ks})^2} u \sqrt{u^2 + v^2}\f$ and
+ *\f$\tau_{y} = \frac{\kappa^2}{(ln\frac{12h}{ks})^2} v \sqrt{u^2 + v^2}\f$
+ *
+ * with the dimensionless Karman's constant \f$\mathrm{\kappa}\f$, the quivalent sand roughness
+ * \f$\mathrm{ks}\f$ in \f$\mathrm{[m]}\f$ and the water depth \f$\mathrm{h}\f$
+ * in \f$\mathrm{[m]}\f$.
+ *
  * The bottom shear stress is needed to calculate on the one hand the loss of
  * momentum due to bottom friction and on the other hand the bedload transport rate.
  *
  * The LET mobility model is used to limit the friction for small water
  * depths if a roughness height > 0.0 is provided (default roughnessHeight = 0.0).
+ *
  */
 
 template <typename VolumeVariables>