@article{IIGUM_2011_4_3_a5,
     author = {I. A. Kazakov},
     title = {A formalization of the {Codd} algebra operations in logic $\mathcal{SHOIN}(D)$},
     journal = {The Bulletin of Irkutsk State University. Series Mathematics},
     pages = {68--73},
     publisher = {mathdoc},
     volume = {4},
     number = {3},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IIGUM_2011_4_3_a5/}
}