From 2054cf64ff1625acb2472d832543af29c9203372 Mon Sep 17 00:00:00 2001
From: Justin Lin <justin.sdk@gmail.com>
Date: Thu, 1 Jul 2021 13:06:28 +0800
Subject: [PATCH] add comment

---
 examples/seashell.scad | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/examples/seashell.scad b/examples/seashell.scad
index 4e290bad..b60c6c9e 100644
--- a/examples/seashell.scad
+++ b/examples/seashell.scad
@@ -1,3 +1,5 @@
+// The math of the shells: https://www.youtube.com/watch?v=pKHWzmxw_NI
+
 use <surface/sf_thickenT.scad>;
 
 alpha = 85;