diff --git a/opfython/core/heap.py b/opfython/core/heap.py
index 6bfaad4..cffd0fa 100644
--- a/opfython/core/heap.py
+++ b/opfython/core/heap.py
@@ -71,7 +71,7 @@ def policy(self, policy):
 
     @property
     def cost(self):
-        """list: List of node's costs.
+        """list: List of nodes' costs.
 
         """
 
@@ -86,7 +86,7 @@ def cost(self, cost):
 
     @property
     def color(self):
-        """list: List of node's colors.
+        """list: List of nodes' colors.
 
         """
 
@@ -101,7 +101,7 @@ def color(self, color):
 
     @property
     def p(self):
-        """list: List of node's values.
+        """list: List of nodes' values.
 
         """
 
@@ -116,7 +116,7 @@ def p(self, p):
 
     @property
     def pos(self):
-        """list: List of node's positioning markers.
+        """list: List of nodes' positioning markers.
 
         """
 
diff --git a/opfython/core/opf.py b/opfython/core/opf.py
index 1b0bd3c..4b4c8dc 100644
--- a/opfython/core/opf.py
+++ b/opfython/core/opf.py
@@ -86,18 +86,30 @@ def distance(self):
 
     @distance.setter
     def distance(self, distance):
-        if distance not in ['bray_curtis', 'canberra', 'chi_squared', 'chord', 'cosine', 'euclidean',
-                            'gaussian', 'log_euclidean', 'log_squared_euclidean', 
-                            'manhattan', 'squared_chord', 'squared_euclidean']:
-            raise e.TypeError('`distance` should be `bray_curtis`, `canberra`, `chi_squared`, '
-                              '`chord`, `cosine`, `euclidean`, `gaussian`, `log_euclidean`, `log_squared_euclidean`, '
-                              '`manhattan`, `squared_chord` or `squared_euclidean`')
+        if distance not in ['additive_symmetric', 'average_euclidean', 'bhattacharyya', 'bray_curtis',
+                            'canberra', 'chebyshev', 'chi_squared', 'chord', 'clark', 'cosine', 'dice',
+                            'divergence', 'euclidean', 'gaussian', 'gower', 'hamming', 'hassanat', 'hellinger',
+                            'jaccard', 'jeffreys', 'jensen', 'jensen_shannon', 'k_divergence', 'kulczynski',
+                            'kullback_leibler', 'log_euclidean', 'log_squared_euclidean', 'lorentzian',
+                            'manhattan', 'matusita', 'max_symmetric', 'mean_censored_euclidean', 'min_symmetric',
+                            'neyman', 'non_intersection', 'pearson', 'sangvi', 'soergel', 'squared', 'squared_chord',
+                            'squared_euclidean', 'statistic', 'topsoe', 'vicis_symmetric1', 'vicis_symmetric2',
+                            'vicis_symmetric3', 'vicis_wave_hedges']:
+            raise e.TypeError('`distance` should be `additive_symmetric`, `average_euclidean`, `bhattacharyya`, '
+                              '`bray_curtis`, `canberra`, `chebyshev`, `chi_squared`, `chord`, `clark`, `cosine`, '
+                              '`dice`, `divergence`, `euclidean`, `gaussian`, `gower`, `hamming`, `hassanat`, `hellinger`, '
+                              '`jaccard`, `jeffreys`, `jensen`, `jensen_shannon`, `k_divergence`, `kulczynski`, '
+                              '`kullback_leibler`, `log_euclidean`, `log_squared_euclidean`, `lorentzian`, `manhattan`, '
+                              '`matusita`, `max_symmetric`, `mean_censored_euclidean`, `min_symmetric`, `neyman`, '
+                              '`non_intersection`, `pearson`, `sangvi`, `soergel`, `squared`, `squared_chord`, '
+                              '`squared_euclidean`, `statistic`, `topsoe`, `vicis_symmetric1`, `vicis_symmetric2`, '
+                              '`vicis_symmetric3` or `vicis_wave_hedges`')
 
         self._distance = distance
 
     @property
     def distance_fn(self):
-        """bool: Distance function to be used.
+        """callable: Distance function to be used.
 
         """
 
diff --git a/opfython/core/subgraph.py b/opfython/core/subgraph.py
index 2cc5ab4..06d8193 100644
--- a/opfython/core/subgraph.py
+++ b/opfython/core/subgraph.py
@@ -95,7 +95,7 @@ def n_features(self, n_features):
 
     @property
     def nodes(self):
-        """list: List of Nodes that belongs to the Subgraph.
+        """list: List of nodes that belongs to the Subgraph.
 
         """
 
@@ -110,7 +110,7 @@ def nodes(self, nodes):
 
     @property
     def idx_nodes(self):
-        """list: List of indexes of ordered nodes.
+        """list: List of ordered nodes indexes.
 
         """
 
diff --git a/opfython/models/knn_supervised.py b/opfython/models/knn_supervised.py
index 083a892..ba5f257 100644
--- a/opfython/models/knn_supervised.py
+++ b/opfython/models/knn_supervised.py
@@ -16,7 +16,8 @@ class KNNSupervisedOPF(OPF):
     """A KNNSupervisedOPF which implements the supervised version of OPF classifier with a KNN subgraph.
 
     References:
-        J. P. Papa and A. X. Falcão. A Learning Algorithm for the Optimum-Path Forest Classifier. Graph-Based Representations in Pattern Recognition (2009).
+        J. P. Papa and A. X. Falcão. A Learning Algorithm for the Optimum-Path Forest Classifier.
+        Graph-Based Representations in Pattern Recognition (2009).
 
     """
 
diff --git a/opfython/subgraphs/knn.py b/opfython/subgraphs/knn.py
index 07c9c38..83c86bc 100644
--- a/opfython/subgraphs/knn.py
+++ b/opfython/subgraphs/knn.py
@@ -342,27 +342,3 @@ def eliminate_maxima_height(self, height):
                 self.nodes[i].cost = np.maximum(self.nodes[i].density - height, 0)
 
         logger.debug('Maxima eliminated.')
-
-    # def eliminate_maxima_area(self, area):
-    #     """Eliminates maxima values in the subgraph that are below the inputted area.
-
-    #     Args:
-    #         area (float): Area's threshold.
-
-    #     """
-
-    #     logger.debug(f'Eliminating maxima above area = {area} ...')
-
-    #     logger.debug('Maxima eliminated.')
-
-    # def eliminate_maxima_volume(self, volume):
-    #     """Eliminates maxima values in the subgraph that are below the inputted volume.
-
-    #     Args:
-    #         volume (float): Volume's threshold.
-
-    #     """
-
-    #     logger.debug(f'Eliminating maxima above volume = {volume} ...')
-
-    #     logger.debug('Maxima eliminated.')