SQL & PL/SQL

Hi,
I have a question regard outer join,

I have table A (Aid, ADesc), Table B(Bid, Bdesc), and Table C (Aid, Bid, Cdesc)
There is data in Table A and B, but Table C is empty
I want to outer join C with A and B with below query

select ADesc,Bdesc, Cdest
from A, B, C
where A.Aid=C.Aid(+) and B.Bid(+)=C.Bid
and A.Aid='XXX' and B.Bid(+)='ZZZ'

The query result show only data in column Adesc , but column BDesc is empty even though there are some data in table B.

How should the query been modified to correctly show ADESC and Bdesc.

Thanks

Vincent