SQL & PL/SQL :: Display Rows Existed In T_SOURCE Table?

How can we display the rows which are existed in T_SOURCE table and which doesn't existed in T_TARGET table using outer join.

My code is as follows.

CREATE TABLE T_SOURCE(sno NUMBER,sname VARCHAR2(20));
CREATE TABLE T_TARGET(sno NUMBER,sname VARCHAR2(20));
INSERT INTO T_SOURCE VALUES(1,'A');
INSERT INTO T_SOURCE VALUES(2,'B');
INSERT INTO T_SOURCE VALUES(3,'C');
INSERT INTO T_SOURCE VALUES(4,'D');
INSERT INTO T_SOURCE VALUES(4,'E');
INSERT INTO T_TARGET VALUES(1,'A');
INSERT INTO T_TARGET VALUES(2,'B');

I tried this but I am getteing all the rows.

select t_source.sno,t_source.sname
FROM t_target,t_source
WHERE t_target.sno(+)=t_source.sno
AND
t_target.sname(+)=t_source.sname