On rectangles and countably generated families
Volume 95 / 1977
                    
                    
                        Fundamenta Mathematicae 95 (1977), 129-139                    
                                        
                        DOI: 10.4064/fm-95-2-129-139                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            