Department of Statistics, Novosibirsk State University of Economics and Management, Novosibirsk, Russian Federation
Department of Statistics, Novosibirsk State University of Economics and Management, Novosibirsk, Russian Federation
Copyright © 2014 E. Yu. Chemezova, K. A. Zaykov et al. This is
an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly cited.