add the TACAS'22 reference

* doc/org/citing.org, doc/spot.bib: There.

doc/spot.bib

@@ -172,6 +172,22 @@
   doi		= {10.4230/LIPIcs.ICALP.2021.123}
 }
 
+@InProceedings{	  casares.22.tacas,
+  author	= {Antonio Casares and Alexandre Duret-Lutz and Klara J.
+		  Meyer and Florian Renkin and Salomon Sickert},
+  title		= {Practical Applications of the {A}lternating {C}ycle
+		  {D}ecomposition},
+  booktitle	= {Proceedings of the 28th International Conference on Tools
+		  and Algorithms for the Construction and Analysis of
+		  Systems},
+  year		= {2022},
+  series	= {Lecture Notes in Computer Science},
+  month		= apr,
+  volume	= {13244},
+  pages		= {99--117},
+  doi		= {10.1007/978-3-030-99527-0_6},
+}
+
 @InProceedings{	  cerna.03.mfcs,
   author	= {Ivana {\v{C}}ern{\'a} and Radek Pel{\'a}nek},
   title		= {Relating Hierarchy of Temporal Properties to Model