diff --git a/extras/free-books.md b/extras/free-books.md
index 260726b..09ff63b 100644
--- a/extras/free-books.md
+++ b/extras/free-books.md
@@ -77,7 +77,6 @@ Name | Author(s)
 [Grinstead and Snell’s Introduction to Probability](https://math.dartmouth.edu/~prob/prob/prob.pdf) |Charles M. Grinstead, J. Laurie Snell
 
 ### Computer Architecture
-[The Elements of Computer Systems - From NAND to Tetris](http://www.nand2tetris.org/course.php) |Noam Nisan, Shimon Schocken
 
 ### Operating Systems
 :-- | :--: