Two observations on a theorem by Coifman
Tom 64 / 1979
                    
                    
                        Studia Mathematica 64 (1979), 191-194                    
                                        
                        DOI: 10.4064/sm-64-3-191-194                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            