diff --git a/machine_learning/multinomial_naive_bayes_classifier.py b/machine_learning/multinomial_naive_bayes_classifier.py
index 2c994f2f8..980aadca8 100644
--- a/machine_learning/multinomial_naive_bayes_classifier.py
+++ b/machine_learning/multinomial_naive_bayes_classifier.py
@@ -1,6 +1,9 @@
 """
 Implementation from scratch of a Multinomial Naive Bayes Classifier.
 The algorithm is trained and tested on the twenty_newsgroup dataset from sklearn to perform text classification
+
+Here the Wikipedia page to understand the theory behind this kind of probabilistic models:
+https://en.wikipedia.org/wiki/Naive_Bayes_classifier
 """