diff --git a/README.md b/README.md
index afd00a4..2293307 100644
--- a/README.md
+++ b/README.md
@@ -11,4 +11,9 @@ PHP project to generate cached SVG price charts
 Extract the files from https://github.com/seigler/Dash-SVG-chart/archive/master.zip where you want to use the chart, or from the command line run `git clone "https://github.com/seigler/Dash-SVG-chart" .` in the folder where you want the charts served from.
 
 ## Usage
-`<img src="path to the folder where you cloned this project">`
\ No newline at end of file
+`<img src="path to the folder where you cloned this project">`
+
+## Credits
+
+* PHP output buffering based on http://www.the-art-of-web.com/php/buffer/
+* Chart appearance based on advice found at http://vis4.net/blog/posts/doing-the-line-charts-right/