@article{KUIPM_1979_a5,
     author = {S. N. Perfilov and R. F. Khabibullin},
     title = {Problem of optimality of iteration processes},
     journal = {Issledovaniya po Prikladnoi Matematike i Informatike},
     pages = {41--50},
     publisher = {mathdoc},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUIPM_1979_a5/}
}