Add reference

kgryte · kgryte · commit dfcd7438638b · 2016-10-21T11:32:00.000-07:00
diff --git a/tools/git/scripts/commit_intervals b/tools/git/scripts/commit_intervals
@@ -3,6 +3,10 @@
 # Prints commit intervals (in seconds).
 #
 # <interval>
+#
+# References:
+#
+# * Kolassa, Carsten, Dirk Riehle, and Michel A. Salim. 2013. "The Empirical Commit Frequency Distribution of Open Source Projects." In *Proceedings of the 9th International Symposium on Open Collaboration*, 18:1–:8. WikiSym '13. New York, NY, USA: ACM. doi:[10.1145/2491055.2491073](http://dx.doi.org/10.1145/2491055.2491073).
 
 # * `git log`
 #   - Show the commit timestamp for each commit.
