On clusters in proximity spaces
Tom 47 / 1959
                    
                    
                        Fundamenta Mathematicae 47 (1959), 205-213                    
                                        
                        DOI: 10.4064/fm-47-2-205-213                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            