Finite-dimensional perturbations of spectral problems and variational approximation methods for eigenvalue problems. Part I. Finite-dimensional perturbations
Tom 36 / 1970
                    
                    
                        Studia Mathematica 36 (1970), 1-76                    
                                        
                        DOI: 10.4064/sm-36-1-1-76                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            