1994, Steklov Mathematical Institute & Supreme Certification Commission of Russia "Habil.": Approximation Rates and Asymptotic Expansions for Some Random Processes; 1978, Novosibirsk State University (Diploma Thesis: Stability Theorems and Estimates of the Rate of Convergence of the Components of Factorizations for Walks Defined on Markov Chains); 1982, Steklov Mathematical Institute , Moscow, PhD: Limit Theorems for Some Types of Random Walks