diff --git a/03_data_science_practice.Rmd b/03_data_science_practice.Rmd
index 2009fca..b9b7d79 100644
--- a/03_data_science_practice.Rmd
+++ b/03_data_science_practice.Rmd
@@ -217,6 +217,8 @@ Luis Darcy Verde Arregoitia (2018) [Good practices for sharing analysis-ready da
 
 Karl Broman and Kara Woo, ["Data organization in spreadsheets"] [@Broman_Woo_2017].
 
+[Data Organization in Spreadsheets for Social Scientists: Formatting problems](https://datacarpentry.org/spreadsheets-socialsci/02-common-mistakes/index.html) -- DataCarpentry lesson
+
 
 <blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">I read &quot;Data analysis without scripting&quot; as &quot;Dystopian moonscape of unrecorded user actions&quot;. I may not be Tableau&#39;s target market. <a href="https://twitter.com/hashtag/rstats?src=hash">#rstats</a></p>&mdash; Gordon Shotwell (/@/gshotwell) <a href="https://twitter.com/gshotwell/status/577485681146097664">March 16, 2015</a></blockquote>
 <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>