On a property of sets of positive measure
Volume 60 / 1967
                    
                    
                        Fundamenta Mathematicae 60 (1967), 187-190                    
                                        
                        DOI: 10.4064/fm-60-2-187-190                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            