@article{ZNSL_1988_168_a7,
     author = {V. O. Kuznetsov},
     title = {On properties of associated quadratic differentials in some extremal problems},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {85--97},
     publisher = {mathdoc},
     volume = {168},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1988_168_a7/}
}