@article{MO_2002_1_a4,
     author = {V. V. Tsukerman},
     title = {Nabla-calculus, continued},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {42--52},
     year = {2002},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2002_1_a4/}
}