@article{DAN_1987_293_3_a15,
     author = {G. L. Shpilker},
     title = {Some differential properties of a commutative hypercomplex},
     journal = {Doklady Akademii Nauk},
     pages = {578--583},
     publisher = {mathdoc},
     volume = {293},
     number = {3},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_293_3_a15/}
}