@article{INTO_2023_223_a6,
     author = {A. V. Kostin},
     title = {Shadow problem and isometric embeddings of pseudospherical surfaces},
     journal = {Itogi nauki i tehniki. Sovremenna\^a matematika i e\"e prilo\v{z}eni\^a. Temati\v{c}eskie obzory},
     pages = {69--78},
     publisher = {mathdoc},
     volume = {223},
     year = {2023},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTO_2023_223_a6/}
}