diff --git a/free-programming-books.md b/free-programming-books.md
index 35779bdc..961f4659 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -1427,6 +1427,7 @@ See also [LaTeX](#latex)
 
 ###Unix
 * [A User's Guide for GNU AWK](http://www.math.utah.edu/docs/info/gawk_toc.html)
+* [Conquering the Command Line](http://www.conqueringthecommandline.com/)
 
 
 ###Vim