[rational-future]

Lucas did see a number of German and Soviet SciFi movies before making Star Wars. Some of the influence in costumes and space ships is quite obvious.

[arethuza]

Another very obvious influence on Star Wars, and specifically the attack on the Death Star, was the UK 1955 movie "The Dam Busters" about the real life WW2 Operation Chastise.

There are amusing clips on YouTube of Star Wars visuals and the The Dam Busters audio and vice-versa - the similarity is pretty close.

Edit: Correction 1995 -> 1955

[kunai]

1995? I think you meant 1955 :)