Resolve "CNN add missing references"

Closes #78 (closed)

book/src/AI-Models/Convolutional-Neural-Networks/Convolutional-Neural-Networks.md

@@ -83,3 +83,7 @@ which further explains some of the special mechanics used in CNNs. It also touch
 If you now actually want to play with this machine learning model check out the jupyter notebook for Convolutional Neural Networks. There we try our luck by guessing what is pictured on 32*32 images. Spoiler: with the limited hardware of a PI we wont have that much luck. But you can try to improve it by changing the network parameters yourself.
 
 Also there is a really good visual representation of a [CNN guessing handwritten digits](https://www.cs.cmu.edu/~aharley/vis/conv/flat.html) by Adam Harley, if you are more the visual type.
+
+## Reference
+
+{{#include ../../References.md:CNN}}