Pultr, Aleš <br/><br/>
Combinatorial, algebraic, and topological representations of groups, semigroups, and categories / 
Aleš Pultr, Věra Trnková ; Czechoslovak Academy of Sciences. 
 - Prague :  Academia,  1980. 
<br/><br/><label>Subjects--Index Terms: </label>მათემატიკა