Invited Talks -- Factorization Forests -- Weighted versus Probabilistic Logics -- Post Correspondence Problem and Small Dimensional Matrices -- Size Complexity of Two-Way Finite Automata -- Matrix Mortality and the ?erný-Pin Conjecture -- Regular Papers -- A Quadratic Upper Bound on the Size of a Synchronizing Word in One-Cluster Automata -- Regular Languages Definable by Majority Quantifiers with Two Variables -- The Inclusion Problem of Context-Free Languages: Some Tractable Cases -- On the Complexity of Deciding Avoidability of Sets of Partial Words -- Closures in Formal Languages and Kuratowski's Theorem -- Rich and Periodic-Like Words -- Traces of Control-Flow Graphs -- Left and Right Synchronous Relations -- An Extension of the Lyndon Schützenberger Result to Pseudoperiodic Words -- Asymptotic Cellular Complexity -- Strongly Regular Grammars and Regular Approximation of Context-Free Languages -- Powers of Regular Languages -- Existence and Nonexistence of Descriptive Patterns -- On Stateless Multihead Finite Automata and Multihead Pushdown Automata -- On Negative Bases -- Crucial Words for Abelian Powers -- Tight Bounds on the Descriptional Complexity of Regular Expressions -- Subshifts, Languages and Logic -- Magic Numbers and Ternary Alphabet -- The Pumping Lemma for Well-Nested Multiple Context-Free Languages -- The Support of a Recognizable Series over a Zero-Sum Free, Commutative Semiring Is Recognizable -- A Game-Theoretic Characterization of Boolean Grammars -- Word Equations with One Unknown -- On Equations over Sets of Numbers and Their Limitations -- Some Remarks on Superposition Based on Watson-Crick-Like Complementarity -- A Weighted ?-Calculus on Words -- Branching-Time Temporal Logics with Minimal Model Quantifiers -- Simulations by Time-Bounded Counter Machines -- WeightedTimed MSO Logics -- Balanced Words Having Simple Burrows-Wheeler Transform -- On the Complexity of Hmelevskii's Theorem and Satisfiability of Three Unknown Equations -- Definability in the Infix Order on Words -- Two-Sided Bounds for the Growth Rates of Power-Free Languages -- On the Decidability of the Equivalence for a Certain Class of Transducers -- Erasing in Petri Net Languages and Matrix Grammars.