@article{MT_2023_26_1_a4,
     author = {M. B. Karmanova},
     title = {The area of surfaces on {sub-Lorentzian} structures of depth two},
     journal = {Matemati\v{c}eskie trudy},
     pages = {93--119},
     publisher = {mathdoc},
     volume = {26},
     number = {1},
     year = {2023},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MT_2023_26_1_a4/}
}