diff --git a/course/lecture/lecture1.md b/course/lecture/lecture1.md
index 88a7338a5542c32c227842e7c2f19927734debe8..1cf21533f9f970420bba82fcc5bb7b7d72e82038 100644
--- a/course/lecture/lecture1.md
+++ b/course/lecture/lecture1.md
@@ -5,6 +5,10 @@
 
 ------
 
+[Part II](lecture2.md)
+
+------
+
 **_Abstract_**
 
 We present in this notebook the **indirect simple shooting** method based on the [Pontryagin Maximum Principle (PMP)](https://en.wikipedia.org/wiki/Pontryagin%27s_maximum_principle) to solve a smooth optimal control problem. By smooth, we mean that the maximization condition of the PMP gives a control law in feedback form (i.e. with respect to the state and the costate) at least [continuously differentiable](https://en.wikipedia.org/wiki/Smoothness#Differentiability_classes).
@@ -18,7 +22,7 @@ The goal of this presentation is that at the end, you will be able to implement
 **_Contents_**
 
 [[_TOC_]]
-    
+
 ## I) Statement of the optimal control problem and necessary conditions of optimality
 
 ### a) Definition of the optimal control problem
@@ -300,3 +304,9 @@ Computing we get,
 ```math
     u(t) = p(t) = (0, \frac{1}{t_f}), \quad \lambda = \frac{1}{t_f}, \quad x(t) = (t, \frac{t}{t_f}).
 ```
+
+------
+
+[Part II](lecture2.md)
+
+------