name a office holder whose predecessor is jacqueline kennedy onassis and has son named lynda bird johnson robb ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_predecessor dbr_Jacqueline_Kennedy_Onassis sep_dot var_uri dbo_child dbr_Lynda_Bird_Johnson_Robb sep_dot var_uri a dbo_OfficeHolder brack_close