diff --git a/free-programming-books.md b/free-programming-books.md
index c08f0b668..e4c0523c4 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -147,6 +147,7 @@
 * [Teradata](#teradata)
 * [TeX](#tex)
 * [Tizen](#tizen)
+* [TLA](#tla)
 * [TypeScript](#typescript)
 * [Unix](#unix)
 * [Verilog](#verilog)