1. J. Balatoni andA. Rényi, Remarks on entropy (in Hungarian with English and Russian summaries),Publ. Math. Inst. Hung. Acad. Sci.,1 (1956), pp. 9–40. German translation under the title “Über den Begriff der Entropie” in the collection of papers: “Arbeiten zur Informationstheorie. I” (Math. Forschungsberichte. IV, Deutscher Verlag der Wissenschaften, Berlin, 1957, pp. 117–134.)
2. A. Rényi, On the dimension and entropy of probability distributions,Acta Math. Acad. Sci. Hung.,10 (1959), pp. 193–215.