@article{TIMM_2003_9_1_a3,
     author = {V. I. Berdyshev},
     title = {Navigation by means of the field of altitudes and its fragment},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {26--37},
     year = {2003},
     volume = {9},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2003_9_1_a3/}
}