bib: add Elmas POPL'09

biblio.bib

@@ -1450,6 +1450,19 @@
   pages		= {711--804}
 }
 
+@InProceedings{	  elmas2009:qed,
+  author	= {Tayfun Elmas and Shaz Qadeer and Serdar Tasiran},
+  editor	= {Zhong Shao and
+               Benjamin C. Pierce},
+  title		= {A calculus of atomic actions},
+  booktitle	= {\bibPOPL{2009}},
+  pages		= {2--15},
+  publisher	= {{ACM}},
+  year		= {2009},
+  url		= {https://doi.org/10.1145/1480881.1480885},
+  doi		= {10.1145/1480881.1480885},
+}
+
 @InProceedings{	  emerson2005:symmetry,
   title		= {Dynamic Symmetry Reduction},
   author	= {E. Allen Emerson and Thomas Wahl},