On the congruence $f(x^k) ≡ 0 mod q$, where q is a prime and f is a polynomial
Volume 51 / 1988
                    
                    
                        Acta Arithmetica 51 (1988), 195-200                    
                                        
                        DOI: 10.4064/aa-51-3-195-200                    
                                    
                                                                
                             
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            