@article{PDMA_2012_5_a7,
     author = {S. N. Kjazhin and V. M. Fomichev},
     title = {Structural properties of primitive systems of natural numbers},
     journal = {Prikladnaya Diskretnaya Matematika. Supplement},
     pages = {16--18},
     year = {2012},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDMA_2012_5_a7/}
}