diff --git a/journal/logbook.md b/journal/logbook.md
index 64881a6c6deff9423ec1e39ead4593643917f9b1..437e0c819ae51a4edd967668f21b92f1349a4ed2 100644
--- a/journal/logbook.md
+++ b/journal/logbook.md
@@ -1,5 +1,7 @@
 # MOOC Reproducible Research: my logbook
 
+# Mission 1
+
 ## Module 1: Cahier de notes, cahier de laboratoire
 
 I have started this module on June 5.
@@ -45,7 +47,7 @@ and completed several quizzes relsted to th each thematique of this Module.
 - How to use GitLab history
 - beginnig of the work with Jupyter notebook and commited it
 
-# Mission 2 - Module 2.
+# Mission 3 - Module 2.
 
 ## Excercice 02 (1st part)
 
@@ -90,3 +92,19 @@ Prior to the launch, a teleconference was held to assess the risk of taking off
     2. **Key data points were excluded** from the analysis.
     3. **the uncertainity of the logistic regression estimates was not taken into accounts**, leading to overconfidence in the predictions.
 
+# Mission 4 - Module 3
+
+## Exercise 03 (1st part)
+
+In this task, the following steps were perfomed:
+
+- The small part of code was implemented and modified to check whether the local CSV file already exists.
+- If the file does not exist, it is downloaded from the Réseau Sentinelles server and saved localy.
+- If the file is present, the local copy was used instead of re-downloading the data.
+- Necessary comments were added in the code to explain the logic and purpose of each step:
+    - # Firstly, check if the local CSV file already exists.
+    - # Secondly, if the file does not exist, download it from the official URL and save it locally.
+    - # Thirdly,this ensures that the analysis uses a consistent local copy and avoids repeated downloads.
+
+A comparative analysis with the reference solution confirmed the implementation was correct.
+