1. J. L. Doob,Stochastic Processes, Wiley, Chapman and Hall, New York (1953).
2. V. V. Petrov,Sums of Independent Random Variables [in Russian], Nauka, Moscow (1972).
3. Yu. V. Prokhorov and Yu. A. Rozanov,Probability Theory [in Russian], Nauka, Moscow (1973).
4. V. A. Statulevichus, “Limit theorems for densities and asymptotic decompositions for distributions of sums of independent random variables,”Teor. Veroyatn Primen.,10, No. 4, 645–659 (1965).
5. N. G. Ushakov, “Some inequalities for the characteristic functions of unimodal distributions,”Teor. Veroyatn. Primen.,26, No. 3, 606–609 (1981).