diff --git a/README.md b/README.md
index 418c569b5e35ed0b20d683416af43da8a4647b35..ac224edf2a49938be9ef2caab2251c45a4e3026a 100644
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@@ -38,6 +38,8 @@ Here is a 50% scale flexure (.010" beams, .015" gaps) machined from .020" thick
 
 <img src='images/flexure-0.5-penny.jpg' width=300px>
 
+Here is a paper about micromachining aluminum using tools with diamond-like coatings: <a href='https://pdfs.semanticscholar.org/a9d5/532adaf5fa1b22940a921fc9cdf2ea76b555.pdf'>Diamond coatings for micro end mills: Enabling the dry machining of aluminum at the micro-scale, Heaney et. al.</a>
+
 
 
 ## [Fablight fiber laser](http://cba.mit.edu/tools/display/?type=tool&id=fablight_3000_laser_cutter)