@article{JGG_2019_23_1_JGG_2019_23_1_a8,
     author = {V. Mileikovskyi },
     title = {A {Task} {About} {Spheres} and {Cones,} {Applicable} in {Jet} {Theory}},
     journal = {Journal for geometry and graphics},
     pages = {99--114},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {2019},
     url = {http://geodesic.mathdoc.fr/item/JGG_2019_23_1_JGG_2019_23_1_a8/}
}