which famous writer was married to vivian mercier and had a son named eiléan ní chuilleanáin ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_spouse dbr_Vivian_Mercier sep_dot var_uri dbo_child dbr_Eiléan_Ní_Chuilleanáin sep_dot var_uri a dbo_Writer brack_close