Salomaa Arto Salomaa & Rozenberg Grzegorz Rozenberg 
Developments In Language Theory Ii, At The Crossroads Of Mathematics, Computer Science And Biology [PDF ebook] 

The contributions of the proceedings cover almost all parts of the theory of formal languages from pure theoretical investigations to applications to programming languages. Main topics are combinatorial properties of words, sequences of words and sets of words, grammar systems and grammars with controlled derivations, generation of higher-dimensional objects and graphs, trace languages, numerical parameters of automata and languages.