From eaa31af88ada192f6b198b1be2cc87a9feaf7057 Mon Sep 17 00:00:00 2001
From: lilabdel <44303516+lilabdel@users.noreply.github.com>
Date: Mon, 26 Nov 2018 04:20:55 +0000
Subject: [PATCH] Book about mathematics (#23442)

* Book about mathematics

Add the link to the book "the princeton companion to mathematics"

* Improved formatting
---
 guide/english/mathematics/index.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/guide/english/mathematics/index.md b/guide/english/mathematics/index.md
index bd7ce4e242..57f46be9fd 100644
--- a/guide/english/mathematics/index.md
+++ b/guide/english/mathematics/index.md
@@ -112,5 +112,6 @@ The `math` module can also be imported as follows, and the usage difference is i
 
 Documentation reference: <a href='https://docs.python.org/2/library/math.html' target='_blank' rel='nofollow'>Python 2</a> | <a href='https://docs.python.org/3/library/math.html' target='_blank' rel='nofollow'>Python 3</a>
 
-### Additional resources
-Animated visualizations of mathematical concepts can be found at [3 Blue 1 Brown](http://www.3blue1brown.com/) and [Khan Academy](https://www.khanacademy.org/).
+#### Additional resources
+- Animated visualizations of mathematical concepts can be found at [3 Blue 1 Brown](http://www.3blue1brown.com/) and [Khan Academy](https://www.khanacademy.org/).
+- A very nice book about Mathematics named "The Princeton Companion to Mathematics", clear and very easy to understand. You can find a pdf copy [here](https://isidore.co/calibre/get/pdf/4662).