SELECT with outer joins - how to?

I need to select from 3 tables A,B and C. It has to be an outer join from table A, i.e. I need ALL records from A.

"A" can have multiple corresponding records in B and we need them all. Entries from B has exactly 1 corresponding record in C.

I have to get data in ONE select statement. Can you help with the syntax?

Example of data:

A: WERKS=1234

B: WERKS=1234, OBJID=100000

B: WERKS=1234, OBJID=100001

B: WERKS=1234, OBJID=100002

C: OBJID=100001, COSTCTR=0023

Thanks a lot.