diff --git a/README.md b/README.md
index ac56dce..826d194 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,7 @@ Graphics and infographics
 * Risposta relativa dei coni dell'occhio: [tex source](https://github.com/ulaulaman/tikzdraw/blob/master/risposta_coni.tex) | [pdf](https://github.com/ulaulaman/tikzdraw/blob/master/pdf/risposta_coni.pdf)
 * Riflessione e rifrazione: [tex source](https://github.com/ulaulaman/tikzdraw/blob/master/riflessione-rifrazione.tex) | [pdf](https://github.com/ulaulaman/tikzdraw/blob/master/pdf/riflessione-rifrazione.pdf)
 * Convection in a glass of water: [tex source](https://github.com/ulaulaman/tikzdraw/blob/master/convezione.tex) | [pdf](https://github.com/ulaulaman/tikzdraw/blob/master/pdf/ghiaccio.pdf)
+* Spin: [tex source](https://github.com/ulaulaman/tikzdraw/blob/master/spin.tex) | [pdf](https://github.com/ulaulaman/tikzdraw/blob/master/pdf/spin.pdf)
 
 ## Infographics