diff --git a/pdf/README.md b/pdf/README.md
index 8258c459..06d051cf 100644
--- a/pdf/README.md
+++ b/pdf/README.md
@@ -58,3 +58,4 @@
 | 2020 | [JosephSullivan CSO](2020-JosephSullivan_CSO.pdf) |
 | 2020 | [Website Fingerprinting with Website Oracles](2020-Website_Fingerprinting_with_Website_Oracles.pdf) |
 | 2020 | [Why We Still Cant Browse in Peace On the Uniqueness and Reidentifiability of Web Browsing Histories](2020-Why_We_Still_Cant_Browse_in_Peace_On_the_Uniqueness_and_Reidentifiability_of_Web_Browsing_Histories.pdf) |
+| 2021 | [How Gamification Affects Software Developers Cautionary Evidence from a Natural Experiment on GitHub](2021-How_Gamification_Affects_Software_Developers_Cautionary_Evidence_from_a_Natural_Experiment_on_GitHub.pdf) |