Undirected strict gammoids
Tom 120 / 1984
                    
                    
                        Fundamenta Mathematicae 120 (1984), 1-5                    
                                        
                        DOI: 10.4064/fm-120-1-1-5                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            