@article{ISU_2007_7_2_a5,
     author = {N. M. Medvedeva},
     title = {Research of stability for extremal rotation surfaces},
     journal = {Izvestiya of Saratov University. Mathematics. Mechanics. Informatics},
     pages = {25--32},
     publisher = {mathdoc},
     volume = {7},
     number = {2},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ISU_2007_7_2_a5/}
}