diff --git a/doc/doxygen/dumux.bib b/doc/doxygen/dumux.bib
index 987c42191e7181995eb5a1975fed6b6f163baeb0..38e4463199ccb481152e68de01901ef2c80deb96 100644
--- a/doc/doxygen/dumux.bib
+++ b/doc/doxygen/dumux.bib
@@ -2114,3 +2114,15 @@ author = {F. Fichot and F. Duval and N. Trégourès and C. Béchaud and M. Quint
   year = {1940},
   pages = {529–558}
 }
+
+@book{NocedalWright2006,
+  title     = {{Numerical Optimization}},
+  author    = {Nocedal, Jorge and Wright, Stephen},
+  ISBN = {9780387303031},
+  DOI = {10.1007/978-0-387-40065-5},
+  publisher = {Springer},
+  series    = {Springer Series in Operations Research and Financial Engineering},
+  edition   = {2},
+  year      = {2006},
+  address   = {New York, NY}
+}
diff --git a/dumux/nonlinear/leastsquares.hh b/dumux/nonlinear/leastsquares.hh
index 42e1def5ddd7e4511037d4bf8fbedc4e3ec6de16..af5fdccc5924fa10f6b3f0b56ab3a76b32b03663 100644
--- a/dumux/nonlinear/leastsquares.hh
+++ b/dumux/nonlinear/leastsquares.hh
@@ -406,6 +406,7 @@ namespace Dumux::Optimization {
 /*!
  * \ingroup Nonlinear
  * \brief Creates a nonlinear least squares solver with \f$n\f$ model parameters and \f$m\f$ observations
+ * For a detailed description of the mathematical background see \cite NocedalWright2006
  * \param f The residual functional to minimize the norm of (\f$ f: \mathbb{R}^n \mapsto \mathbb{R}^m \f$)
  * \param x0 Initial guess for the parameters (vector of size \f$n\f$)
  * \param size The number of observations (\f$m\f$)