@article{zu220629,
          number = {4},
           title = {On the one extremal problem on the Riemann sphere},
          author = {A. L. Targonskii and I. Targonskaya},
       publisher = {SciPress Ltd., Switzerland},
            year = {2016},
           pages = {1--7},
         journal = {International Journal of Advanced Research in Mathematics},
        keywords = {Inner radius of domain, quadratic differential, piecewise-separating transformation, Green
function, radial systems of points, logarithmic capacity, variational formula},
             url = {http://eprints.zu.edu.ua/20629/},
        abstract = {Sharp estimates of product of inner radii for pairwise disjoint domains are obtained. In
particular, we solve an extremal problem in the case of arbitrary finite number of rays containing
arbitrary even number of free poles}
}