How do you get the other 3 zombie maps in black ops?

i want to know how to get the other 3 zombie maps i.e. der riese, vertuct not sure if those are the names thoughHow do you get the other 3 zombie maps in black ops?
For now, the only way to get the World at War maps in Black Ops is when you buy the Hardened and Prestige editions of the game. There has been no official announcement that the World at War maps will be released for sale to everyone in Black Ops, however Activision has never missed a chance to make some extra money, and this would certainly do the job.



You could also try buying the code for the maps from a person who bought the limited editions of the game and are selling the code. This happens for every game with such a preorder or limited edition download bonus.How do you get the other 3 zombie maps in black ops?
it was in limited edition sorry