On a General Theorem of Number Theory Leading to the Gibbs,   Bose--Einstein, and Pareto Distributions as well as to the Zipf--Mandelbrot   Law for the Stock Market
  The notion of density of a finite set is introduced. We prove a general theorem of set theory which refines the Gibbs, Bose--Einstein, and Pareto distributions as well as the Zipf law. 
V.P. Maslov