Use MINUS.

Example : Three table T1, T2 and T3.
T1 Contains :
1
2
3
4
5
6
7
8
9
10

T2 contains :
2
3
4
5

T3 contains :
6
7

The Query :
select * from t1
minus
select * from t2
minus
select * from t3

will return :
1
8
9
10

Works for you ???