return me the papers written by " H. V. Jagadish " and " Yunyao Li " on PVLDB . 
return H. V. Jagadish ;return Yunyao Li ;return papers written by #1 ;return papers written by #2 ;return #3 that are on PVLDB ;return #4 that are on PVLDB ;return #5 ,  #6
['select', 'select', 'project', 'project', 'filter', 'filter', 'union']