@article{ZNSL_1991_196_a11,
     author = {A. Yu. Solinin},
     title = {Some extremal problems in the class $\Sigma(\tau)$},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {138--153},
     year = {1991},
     volume = {196},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1991_196_a11/}
}