diff --git a/apps/graph/cartesian_function.cpp b/apps/graph/cartesian_function.cpp
index b2d56b274..a6993003e 100644
--- a/apps/graph/cartesian_function.cpp
+++ b/apps/graph/cartesian_function.cpp
@@ -101,6 +101,8 @@ char CartesianFunction::symbol() const {
 }
 
 CartesianFunction::Point CartesianFunction::brentAlgorithm(double ax, double bx, Evaluation evaluate, Context * context) const {
+  /* Bibliography: R. P. Brent, Algorithms for finding zeros and extrema of
+   * functions without calculating derivatives */
   if (ax > bx) {
     return brentAlgorithm(bx, ax, evaluate, context);
   }
diff --git a/poincare/include/poincare/expression.h b/poincare/include/poincare/expression.h
index 7e997b24e..e5153e509 100644
--- a/poincare/include/poincare/expression.h
+++ b/poincare/include/poincare/expression.h
@@ -242,11 +242,10 @@ protected:
    *   1 if e1 > e2
    *   -1 if e1 < e2
    *   0 if e1 == e
-   * Following the order described in Computer Algebra and Symbolic Computation,
-   * Joel S. Cohen (section 3.1). The order groups like terms together to avoid
-   * quadratic complexity when factorizing addition or multiplication. For
-   * example, it groups terms with same bases together (ie Pi, Pi^3)  and with
-   * same non-rational factors together (ie Pi, 2*Pi).
+   * The order groups like terms together to avoid quadratic complexity when
+   * factorizing addition or multiplication. For example, it groups terms with
+   * same bases together (ie Pi, Pi^3)  and with same non-rational factors
+   * together (ie Pi, 2*Pi).
    * Because SimplificationOrder is a recursive call, we sometimes enable its
    * interruption to avoid freezing in the simplification process. */
   static int SimplificationOrder(const Expression * e1, const Expression * e2, bool canBeInterrupted = false);
diff --git a/poincare/src/derivative.cpp b/poincare/src/derivative.cpp
index 6e98add7c..c28acf11d 100644
--- a/poincare/src/derivative.cpp
+++ b/poincare/src/derivative.cpp
@@ -92,8 +92,6 @@ template<typename T>
 T Derivative::riddersApproximation(VariableContext<T> xContext, AngleUnit angleUnit, T x, T h, T * error) const {
   /* Ridders' Algorithm
    * Blibliography:
-   * - Press, W. H., Teukolsky, S. A., Vetterling, W. T., & Flannery, B. P.
-   * (1992). Numerical recipies in C.
    * - Ridders, C.J.F. 1982, Advances in Engineering Software, vol. 4, no. 2,
    * pp. 75–76. */
 
diff --git a/poincare/src/integral.cpp b/poincare/src/integral.cpp
index 8fb5ad914..b90d1070d 100644
--- a/poincare/src/integral.cpp
+++ b/poincare/src/integral.cpp
@@ -81,8 +81,8 @@ T Integral::functionValueAtAbscissa(T x, VariableContext<T> xContext, AngleUnit
 template<typename T>
 T Integral::lagrangeGaussQuadrature(T a, T b, VariableContext<T> xContext, AngleUnit angleUnit) const {
   /* We here use Gauss-Legendre quadrature with n = 5
-   * Gauss-Legendre abscissae and weights taken from
-   * http://www.holoborodko.com/pavel/numerical-methods/numerical-integration/*/
+   * Gauss-Legendre abscissae and weights can be found in
+   * C/C++ library source code. */
   const static T x[10]={0.0765265211334973337546404, 0.2277858511416450780804962, 0.3737060887154195606725482, 0.5108670019508270980043641,
    0.6360536807265150254528367, 0.7463319064601507926143051, 0.8391169718222188233945291, 0.9122344282513259058677524,
    0.9639719272779137912676661, 0.9931285991850949247861224};