@article{10_21136_MB_1998_126071,
     author = {Kar\'asek, Ji\v{r}{\'\i}},
     title = {Cardinal and ordinal arithmetics of $n$-ary relational systems and $n$-ary ordered sets},
     journal = {Mathematica Bohemica},
     pages = {249--262},
     publisher = {mathdoc},
     volume = {123},
     number = {3},
     year = {1998},
     doi = {10.21136/MB.1998.126071},
     mrnumber = {1645434},
     zbl = {0933.08001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/MB.1998.126071/}
}