From 2281cc69ee493009716d568dbc13aaea096315a0 Mon Sep 17 00:00:00 2001
From: vin <53119120+vin-ux@users.noreply.github.com>
Date: Mon, 25 Oct 2021 22:51:49 +0530
Subject: [PATCH] One book added in GUI section (#6425)

---
 books/free-programming-books-subjects.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/books/free-programming-books-subjects.md b/books/free-programming-books-subjects.md
index 492535de5..184fb6aa8 100644
--- a/books/free-programming-books-subjects.md
+++ b/books/free-programming-books-subjects.md
@@ -287,6 +287,7 @@ Books that cover a specific programming language can be found in the  [BY PROGRA
 * [Search User Interfaces](http://searchuserinterfaces.com/book/) - Marti A. Hearst
 * [The GLib/GTK+ Development Platform](https://people.gnome.org/~swilmet/glib-gtk-dev-platform.pdf) - Sébastien Wilmet (PDF)
 * [Web Design Primer](https://pressbooks.library.ryerson.ca/webdesign/) - Richard Adams, Ahmed Sagarwala
+* [Web Style Guide Online](https://www.webstyleguide.com/wsg3/index.html) - Patrick J. Lynch and Sarah Horton
 
 
 ### Information Retrieval