@article{verkhoturov_sergeyeva_2000,  title={
       },  volume={20},  ISSN={0101-7438},  url={https://doi.org/10.1590/S0101-74382000000200007},  DOI={10.1590/S0101-74382000000200007},  number={2},  journal={Pesquisa Operacional},  publisher={Sociedade Brasileira de Pesquisa Operacional},  author={Verkhoturov, M.A. and Sergeyeva, O.Y.},  year={2000},  month={Dec},  pages={233–246} }