Bounds for quadratic Waring's problem
Tom 104 / 2002
                    
                    
                        Acta Arithmetica 104 (2002), 155-164                    
                                        
                        MSC: 11E12, 11E06.                    
                                        
                        DOI: 10.4064/aa104-2-5                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            