diff --git a/mapytex/calculus/core/renders/tree2tex.py b/mapytex/calculus/core/renders/tree2tex.py
index e8a2a68..8c9d74c 100644
--- a/mapytex/calculus/core/renders/tree2tex.py
+++ b/mapytex/calculus/core/renders/tree2tex.py
@@ -210,6 +210,10 @@ def tree2tex(tree):
 
     It calls __tex__ to render MOs.
 
+    :param tree: tree to render
+
+    :example:
+
     >>> from ..tree import Tree
     >>> t = Tree.from_str("2+3*4")
     >>> tree2tex(t)
diff --git a/mapytex/calculus/core/renders/tree2txt.py b/mapytex/calculus/core/renders/tree2txt.py
index 87304c2..144f666 100644
--- a/mapytex/calculus/core/renders/tree2txt.py
+++ b/mapytex/calculus/core/renders/tree2txt.py
@@ -226,6 +226,10 @@ def tree2txt(tree):
 
     It calls __txt__ to render MOs.
 
+    :param tree: tree to render
+
+    :example:
+
     >>> from ..tree import Tree
     >>> t = Tree.from_str("2+3*4")
     >>> tree2txt(t)