@article{DM_1989_1_4_a7,
     author = {I. P. Chukhrov},
     title = {Maximal cardinality of the shadow of an antichain},
     journal = {Diskretnaya Matematika},
     pages = {78--85},
     publisher = {mathdoc},
     volume = {1},
     number = {4},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1989_1_4_a7/}
}