1. An explanation of the first digit phenomenon;Cohen;J. Combin. Theory, Ser. A,1976
2. P. Diaconis, “Limits of Measures of the Integers with Application to Random Number Generators and the Distribution of Leading Digits,” Memo. NS-211, Department of Statistics, Harvard University.
3. On the frequency of use of the different digits in natural numbers;Newcomb;Amer. J. Math.,1881
4. The first digit problem;Raimi;Amer. Math. Monthly,1976