diff --git a/src/bib.bib b/src/bib.bib
index 292c5ea..1c2e2e2 100644
--- a/src/bib.bib
+++ b/src/bib.bib
@@ -849,3 +849,12 @@
   year={2018},
   publisher={Elsevier}
 }
+
+@inproceedings{du2011tilt,
+  title={Tilt \& touch: Mobile phone for 3D interaction},
+  author={Du, Yuan and Ren, Haoyi and Pan, Gang and Li, Shjian},
+  booktitle={Proceedings of the 13th international conference on Ubiquitous computing},
+  pages={485--486},
+  year={2011},
+  organization={ACM}
+}