Where is a good place to get posters of Baltimore and DC?

For a project, I need posters of Baltimore and DC. I still need a poster of the aquarium or Inner Harbor. But I've called gift shops, the aquarium, and even the public library. No luck yet. Any suggestions? Thanks.Where is a good place to get posters of Baltimore and DC?
Both are available at the below URL.



This is my help from Washington, D.C. United States of America.