diff --git a/trees_and_graphs/tree_level_traversal.py b/trees_and_graphs/tree_level_traversal.py
index 15afaee..6317eff 100644
--- a/trees_and_graphs/tree_level_traversal.py
+++ b/trees_and_graphs/tree_level_traversal.py
@@ -1,3 +1,7 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# author: bt3gl
+
 # Given the root of a binary tree, return the level order traversal of its nodes' values. 
 # (i.e., from left to right, level by level).