diff --git a/publist.org b/publist.org
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--- a/publist.org
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@@ -3,36 +3,39 @@
   [[file:en/publications.org][English]] and [[file:fr/publications.org][French]] versions of the bibliography page.
 
 * 2021
-  1. Rémi Segretain, Laurent Trilling, Nicolas Glade, Sergiu Ivanov:
+  1. Sergiu Ivanov, Sergey Verlan: /Single semi-contextual
+     insertion-deletion systems./ Nat. Comput. 20(4): 703-712 (2021)
+
+  2. Rémi Segretain, Laurent Trilling, Nicolas Glade, Sergiu Ivanov:
      /Who Plays Complex Music? On the Correlations Between Structural
      and Behavioral Complexity Measures in Sign Boolean Networks./
      Accepted to the 21th IEEE International Conference on
      BioInformatics and BioEngineering October 25-27, 2021,
      Kragujevac, Serbia.
 
-  2. Artiom Alhazov, Rudolf Freund, Sergiu Ivanov, Marion Oswald:
+  3. Artiom Alhazov, Rudolf Freund, Sergiu Ivanov, Marion Oswald:
      /Relations between Control Mechanisms for Sequential Grammars./
      Fundam. Informaticae 181(2-3): 239-271 (2021)
 
-  3. Artiom Alhazov, Rudolf Freund, Sergiu Ivanov: /P systems with
+  4. Artiom Alhazov, Rudolf Freund, Sergiu Ivanov: /P systems with
      limited number of objects./ J. Membr. Comput. 3(1): 1-9 (2021)
 
-  4. Artiom Alhazov, Rudolf Freund, Sergiu Ivanov: /When catalytic
+  5. Artiom Alhazov, Rudolf Freund, Sergiu Ivanov: /When catalytic
      P systems with one catalyst can be computationally complete./
      J. Membr. Comput. 3(3): 170-181 (2021)
 
-  5. Jérémie Pardo, Sergiu Ivanov, Franck Delaplace: /Sequential
+  6. Jérémie Pardo, Sergiu Ivanov, Franck Delaplace: /Sequential
      reprogramming of biological network fate./
      Theor. Comput. Sci. 872: 97-116 (2021)
 
-  6. Rémi Segretain, Sergiu Ivanov, Laurent Trilling, Nicolas Glade:
+  7. Rémi Segretain, Sergiu Ivanov, Laurent Trilling, Nicolas Glade:
      /A Methodology for Evaluating the Extensibility of Boolean
      Networks’ Structure and Function./ In: Benito R.M., Cherifi C.,
      Cherifi H., Moro E., Rocha L.M., Sales-Pardo M. (eds) Complex
      Networks & Their Applications IX. COMPLEX NETWORKS 1. Studies in
      Computational Intelligence, vol 944. Springer, Cham. (2021)
 
-  7. Elio Nushi, Victor-Bogdan Popescu, José Ángel Sánchez Martín,
+  8. Elio Nushi, Victor-Bogdan Popescu, José Ángel Sánchez Martín,
      Sergiu Ivanov, Eugen Czeizler, Ion Petre: /Network modeling
      methods for precision medicine./ CoRR abs/2104.09206 (2021)