diff --git a/Principal_component_analysis/doc/Principal_component_analysis/CGAL/barycenter.h b/Principal_component_analysis/doc/Principal_component_analysis/CGAL/barycenter.h
index 43337c94629..6fc362ec42e 100644
--- a/Principal_component_analysis/doc/Principal_component_analysis/CGAL/barycenter.h
+++ b/Principal_component_analysis/doc/Principal_component_analysis/CGAL/barycenter.h
@@ -14,11 +14,11 @@ weighted points. The user can also optionally pass an explicit kernel,
 in case the default, based on `Kernel_traits` is not sufficient. The
 dimension is also deduced automatically.
 
-\sa `CGAL::centroid` 
 */
 /// @{
 
 /*!
+
 computes the barycenter of a non-empty set of 2D or 3D weighted
 points.
 
@@ -34,6 +34,10 @@ CGAL::Kernel_traits<
 `std::pair<K::Point_2, K::FT>` or `std::pair<K::Point_3, K::FT>`.
 
 \pre first != beyond, and the sum of the weights is non-zero.
+
+\sa `CGAL::centroid()`
+\sa \link barycenter `CGAL::barycenter()` \endlink
+
 */
 template < typename InputIterator >
 Deduced
@@ -49,7 +53,11 @@ the input values.
 \cgalRequires The value type of `InputIterator` must be
 `std::pair<K::Point_2, K::FT>` or `std::pair<K::Point_3, K::FT>`.
 
-\pre first != beyond, and the sum of the weights is non-zero. 
+\pre first != beyond, and the sum of the weights is non-zero.
+
+\sa `CGAL::centroid()`
+\sa \link barycenter `CGAL::barycenter()` \endlink
+
 */
 template < typename InputIterator, typename K >
 Deduced
diff --git a/Principal_component_analysis/doc/Principal_component_analysis/CGAL/centroid.h b/Principal_component_analysis/doc/Principal_component_analysis/CGAL/centroid.h
index 97ffe2ba8c1..166b60ab58a 100644
--- a/Principal_component_analysis/doc/Principal_component_analysis/CGAL/centroid.h
+++ b/Principal_component_analysis/doc/Principal_component_analysis/CGAL/centroid.h
@@ -20,8 +20,6 @@ computes the centroid of the tetrahedron edges (3D segments) and
 specifying a dimension 2 computes the centroid of the tetrahedron
 facets (3D triangles).
 
-\sa \ref barycenter
-
 */
 /// @{
 
@@ -53,6 +51,10 @@ The value type must be either `K::Point_3`, `K::Segment_3`,
 of balls the user must call the function with value type `K::Sphere_3`
 and with dimension tag of 3. The tag must range between
 `Dimension_tag<0>` and `Dimension_tag<3>`.
+
+\sa `CGAL::barycenter()`
+\sa \link centroid `CGAL::centroid()` \endlink
+
 */
 template < typename InputIterator, typename Tag >
 Deduced
@@ -82,6 +84,10 @@ The value type must be either `K::Point_3`, `K::Segment_3`,
 of balls the user must call the function with value type `K::Sphere_3`
 and with dimension tag of 3. The tag must range between
 `Dimension_tag<0>` and `Dimension_tag<3>`.
+
+\sa `CGAL::barycenter()`
+\sa \link centroid `CGAL::centroid()` \endlink
+
 */
 template < typename InputIterator, typename K, typename Tag >
 Deduced