@article{VMP_2002_3_1_a5,
     author = {M. Yu. Kokurin and V. V. Klyuchev},
     title = {Necessary conditions for the power convergence rate of a class of iterative
},
     journal = {Numerical methods and programming},
     pages = {93--109},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMP_2002_3_1_a5/}
}