@article{TIMM_1998_5_a25,
     author = {L. D. Popov},
     title = {About accuracy of the solution of internal subproblems in the {Hestenes{\textendash}Powell} method},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {381--386},
     year = {1998},
     volume = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_1998_5_a25/}
}