which river's source place is unorganized south nipissing district and mouth in madawaska river ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_sourcePlace dbr_Unorganized_South_Nipissing_District sep_dot var_uri dbo_riverMouth dbr_Madawaska_River_ attr_open Ontario attr_close sep_dot var_uri a dbo_River brack_close