On the systems of tournaments
Volume 2 / 1951
                    
                    
                        Colloquium Mathematicum 2 (1951), 286-290                    
                                        
                        DOI: 10.4064/cm-2-3-4-286-290                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            