diff --git a/pina/graph.py b/pina/graph.py
index 74dc91f..3cd1322 100644
--- a/pina/graph.py
+++ b/pina/graph.py
@@ -63,8 +63,9 @@ class Graph(Data):
         :type pos: torch.Tensor | LabelTensor
         :param edge_attr: Optional tensor of edge_featured ``(E, F')`` where
             ``F'`` is the number of edge features
+        :type edge_attr: torch.Tensor | LabelTensor
         :param bool undirected: Whether to make the graph undirected
-        :param kwargs: Additional keyword arguments passed to the
+        :param dict kwargs: Additional keyword arguments passed to the
             :class:`~torch_geometric.data.Data` class constructor.
         """
         # preprocessing
@@ -201,7 +202,7 @@ class Graph(Data):
 
 class GraphBuilder:
     """
-    A class that allows the simple definition of Graph instances.
+    A class that allows an easy definition of :class:`Graph` instances.
     """
 
     def __new__(
@@ -217,25 +218,25 @@ class GraphBuilder:
         Compute the edge attributes and create a new instance of the
         :class:`~pina.graph.Graph` class.
 
-        :param pos: A tensor of shape `(N, D)` representing the positions of `N`
-            points in `D`-dimensional space.
+        :param pos: A tensor of shape ``(N, D)`` representing the positions of
+            ``N`` points in ``D``-dimensional space.
         :type pos: torch.Tensor or LabelTensor
-        :param edge_index: A tensor of shape `(2, E)` representing the indices
+        :param edge_index: A tensor of shape ``(2, E)`` representing the indices
             of the graph's edges.
         :type edge_index: torch.Tensor
-        :param x: Optional tensor of node features of shape `(N, F)`, where `F`
-            is the number of features per node.
+        :param x: Optional tensor of node features of shape ``(N, F)``, where
+            ``F`` is the number of features per node.
         :type x: torch.Tensor | LabelTensor, optional
-        :param edge_attr: Optional tensor of edge attributes of shape `(E, F)`,
-            where `F` is the number of features per edge.
+        :param edge_attr: Optional tensor of edge attributes of shape ``(E, F)``
+            , where ``F`` is the number of features per edge.
         :type edge_attr: torch.Tensor, optional
         :param custom_edge_func: A custom function to compute edge attributes.
-            If provided, overrides `edge_attr`.
+            If provided, overrides ``edge_attr``.
         :type custom_edge_func: Callable, optional
         :param kwargs: Additional keyword arguments passed to the
             :class:`~pina.graph.Graph` class constructor.
         :return: A :class:`~pina.graph.Graph` instance constructed using the
-            provided   information.
+            provided information.
         :rtype: Graph
         """
         edge_attr = cls._create_edge_attr(
@@ -274,6 +275,7 @@ class GraphBuilder:
     def _build_edge_attr(pos, edge_index):
         """
         Default function to compute the edge attributes.
+
         :param pos: Positions of the points.
         :type pos: torch.Tensor | LabelTensor
         :param torch.Tensor edge_index: Edge indices.
@@ -289,14 +291,15 @@ class GraphBuilder:
 
 class RadiusGraph(GraphBuilder):
     """
-    A class to build a graph based on a radius.
+    Extends the :class:`~pina.graph.GraphBuilder` class to compute
+    edge_index based on a radius. Each point is connected to all the points
+    within the radius.
     """
 
     def __new__(cls, pos, radius, **kwargs):
         """
-        Extends the :class:`~pina.graph.GraphBuilder` class to compute
-        edge_index based on a radius. Each point is connected to all the points
-        within the radius.
+        Instantiate the :class:`~pina.graph.Graph` class by computing the
+        ``edge_index`` based on the radius provided.
 
         :param pos: A tensor of shape ``(N, D)`` representing the positions of
             ``N`` points in ``D``-dimensional space.
@@ -336,13 +339,14 @@ class RadiusGraph(GraphBuilder):
 
 class KNNGraph(GraphBuilder):
     """
-    A class to build a K-nearest neighbors graph.
+    Extends the :class:`~pina.graph.GraphBuilder` class to compute
+    edge_index based on a K-nearest neighbors algorithm.
     """
 
     def __new__(cls, pos, neighbours, **kwargs):
         """
-        Extends the :class:`~pina.graph.GraphBuilder` class to compute
-        edge_index based on a K-nearest neighbors algorithm.
+        Instantiate the :class:`~pina.graph.Graph` class by computing the
+        ``edge_index`` based on the K-nearest neighbors algorithm.
 
         :param pos: A tensor of shape ``(N, D)`` representing the positions of
             ``N`` points in ``D``-dimensional space.