%0 Journal Article %A Karásek, Jiří %T Double $n$-ary relational structures %J Mathematica Bohemica %D 1997 %P 169-174 %V 122 %N 2 %I mathdoc %U https://geodesic-test.mathdoc.fr/articles/10.21136/MB.1997.125916/ %R 10.21136/MB.1997.125916 %G en %F 10_21136_MB_1997_125916