From fe22d56431aa7ac3305941a7e7096765517b9cf0 Mon Sep 17 00:00:00 2001
From: Debao Zhang <hello@debao.me>
Date: Fri, 7 Nov 2014 10:00:24 +0800
Subject: [PATCH] README: Add reference links for formula information

---
 README.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/README.md b/README.md
index cb9832f..598895f 100644
--- a/README.md
+++ b/README.md
@@ -122,3 +122,9 @@ The package contains a **qtxlsx.pri** file that allows you to integrate the comp
 * http://www.ozgrid.com/Excel/excel-custom-number-formats.htm
 * http://stackoverflow.com/questions/894805/excel-number-format-what-is-409
 * http://office.microsoft.com/en-001/excel-help/create-a-custom-number-format-HP010342372.aspx
+
+### Formula
+
+* http://msdn.microsoft.com/en-us/library/ff533995%28v=office.12%29.aspx
+* http://msdn.microsoft.com/en-us/library/dd906358%28v=office.12%29.aspx
+* http://homepages.ecs.vuw.ac.nz/~elvis/db/Excel.shtml