Two Books made freely available by "M.Lothaire"
(M.Lothaire is a collective name chosen by the authors).

It is all about "combinatorics on words" with theory, algorithms applied to different contexts (text, natural language, speech, bioinformatics).

It is not really known, I just want to share it because it contains interesting material that can be useful and open the mind on some problems that was already tackled by famous mathematicians (in the context of computer science).

Follows the Table of Contents for : Applied Combinatorics on Words

• Core Algorithms
  • Algorithms on words
  • Algorithms on indexes
• Natural language processing
  • Symbolic natural language processing
  • Statistical natural language processing
• Bioinformatics
  • Network expression inference
  • Statistics on words with applications to biological sequences
• Algorithms
  • Analytic approach to pattern matching
  • Periodic structures in words
• Mathematics
  • Counting, coding and sampling with words
  • Words in number theory

Follows the Table of Contents for: Algebraic Combinatorics on Words

• Finite and Infinite Words
• Sturmian Words
• Unavoidable Patterns
• Sesquipowers
• The Plactic Monoid
• Codes
• Numeration Systems
• Periodicity
• Centralizers of Noncommutative Series and Polynomials
• Transformations on words and q-Calculus
• Statistics on Permutations and Words
• Makanin's Algorithm
• Independent Systems of Equations

Follows the links down below:

• Page of the main author containing the 2 books: http://www-igm.univ-mlv.fr/~berstel/Lothaire/
• Applied Combinatorics on Words: http://www-igm.univ-mlv.fr/%7Eberstel/Lothaire/AppliedCW/AppCWContents.html
• Algebraic Combinatorics on Words: http://www-igm.univ-mlv.fr/%7Eberstel/Lothaire/AlgCWContents.html