1. Mathematical Foundations of Information Theory;Khinchin,1957
2. For a general bibliography about nonextensive thermodynamics and updates see: http://tsallis.cat.cbpf.br/biblio.htm
3. Possible generalization of Boltzmann-Gibbs statistics
4. Probability Theory;Rényi,1970
5. Selected Papers of Alfred Rényi, vol. 2;Rényi,1976