1. Babenko, K.: On a problem of Gauss. Soviet Math. Dokl19, 136?140 (1978).
2. Billingesley, P.: Ergodic Theory and Information. New York-London-Sydney: John Wiley. (1965).
3. Bosma, W., Jager, H., Wiedijk, F.: Some metrical observations on the approximation by continued fractions. Indag. Math.45, 281?299 (1983).
4. Iosifescu, M.: A very simple proof of a generalization of the Gauss-Kuzmin-Lévy theorem on continued fractions, and related questions. Rev. Roumaine Math. Pures Appl.37, 901?914 (1992).
5. On the Gauss-Kuzmin-Lévy theorem, II. Preprint (1993).