diff --git a/free-programming-books.md b/free-programming-books.md
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--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -634,7 +634,7 @@
 * [The C book](http://publications.gbdirect.co.uk/c_book/)
 * [The Craft of Text Editing or A Cookbook for an Emacs](http://www.finseth.com/craft/) - Craig A. Finseth
 * [The New C Standard - An Annotated Reference](http://www.knosof.co.uk/cbook/cbook.html)
-
+* [Using C on the UNIX System - David A. Curry](http://www.bitsinthewind.com/about-dac/publications/using-c-on-the-unix-system)
 
 ###C++
 * [C++ Annotations](http://cppannotations.sourceforge.net/)