1 files changed, 6 insertions, 6 deletions
diff --git a/src/Alpha_complex/utilities/README b/src/Alpha_complex/utilities/README
index cc3b2524..0d3d6bfc 100644
--- a/src/Alpha_complex/utilities/README
+++ b/src/Alpha_complex/utilities/README
@@ -10,7 +10,7 @@ where `dim` is the dimension of the homological feature, `b` and `d` are respect
 **Usage**
 `alpha_complex_3d_persistence [options] <input OFF file>`
 where
-`<input OFF file>` is the path to the input point cloud in OFF format.
+`<input OFF file>` is the path to the input point cloud in [nOFF ASCII format](http://www.geomview.org/docs/html/OFF.html).
 
 **Allowed options**
 
@@ -55,7 +55,7 @@ Same as `alpha_complex_3d_persistence`, but using weighted points.
 **Usage**
 `weighted_alpha_complex_3d_persistence [options] <input OFF file> <weights input file>`
 where
-`<input OFF file>` is the path to the input point cloud in OFF format.
+`<input OFF file>` is the path to the input point cloud in [nOFF ASCII format](http://www.geomview.org/docs/html/OFF.html).
 `<input weights file>` is the path to the file containing the weights of the points (one value per line).
 
 **Allowed options**
@@ -85,11 +85,12 @@ and [Regular triangulation](https://doc.cgal.org/latest/Triangulation_3/index.ht
 
 ## `periodic_alpha_complex_3d_persistence` ##
 Same as `alpha_complex_3d_persistence`, but using periodic alpha shape 3d.
+Refer to the [CGAL's 3D Periodic Triangulations User Manual](https://doc.cgal.org/latest/Periodic_3_triangulation_3/index.html) for more details.
 
 **Usage**
 `periodic_alpha_complex_3d_persistence [options] <input OFF file> <cuboid file>`
 where
-`<input OFF file>` is the path to the input point cloud in OFF format.
+`<input OFF file>` is the path to the input point cloud in [nOFF ASCII format](http://www.geomview.org/docs/html/OFF.html).
 `<cuboid file>` is the path to the file describing the periodic domain. It must be in the format described [here](http://gudhi.gforge.inria.fr/doc/latest/fileformats.html#FileFormatsIsoCuboid).
 
 **Allowed options**
@@ -142,7 +143,7 @@ where `dim` is the dimension of the homological feature, `b` and `d` are respect
 **Usage**
 `alpha_complex_persistence [options] <input OFF file>`
 where
-`<input OFF file>` is the path to the input point cloud in OFF format.
+`<input OFF file>` is the path to the input point cloud in [nOFF ASCII format](http://www.geomview.org/docs/html/OFF.html).
 
 **Allowed options**
 
@@ -172,6 +173,5 @@ Betti numbers[1] = 2
 Betti numbers[2] = 1
 ```
 
-N.B.: 
-* `alpha_complex_persistence` only accepts OFF files in dimension d.
+N.B.:
 * Filtration values are alpha square values.