1. K. L. Chung and P. Erdős, “On the application of the Borel–Cantelli lemma,” Trans. Am. Math. Soc. 72, 179–186 (1952).
2. P. Erdős and A. Rényi, “On Cantor’s series with convergent 1/q,” Ann. Univ. Sci. Budapest Sect. Math. 2, 93–109 (1959).
3. F. Spitzer, Principles of Random Walk (Van Nostrand, Princeton, N.J., 1964).
4. T. F. Móri and G. J. Székely, “On the Erdős–Rényi generalization of the Borel–Cantelli lemma,” Stud. Sci. Math. Hung. 18, 173–182 (1983).
5. V. V. Petrov, “A note on the Borel–Cantelli lemma,” Stat. Probab. Lett. 58, 283–286 (2002).