diff --git a/README.md b/README.md
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@@ -1,3 +1,6 @@
 # GLSL playground
 
-A few sketches I made while working throught [The Book of Shaders](https://thebookofshaders.com/).
+A few sketches I made while working through [The Book of Shaders](https://thebookofshaders.com/).
+Some of them are notes, some of them are sketches, some of them originated from
+exercises in the book (especially those in the directory `basic`). A lot of the
+code thus isn't mine.