Bradbury's work is often written about it the US and, to a lesser extent, the UK. But he has a wide readership throughout the world. A remarkable insight into how Bradbury is perceived in Russia can be gleaned from friend Pavel's website, www.raybradbury.ru. I don't read Russian, but just clicking around the links is interesting, and if you have the patience to use an internet translation service, you can read some of the site in sort-of English.
Until today, I knew nothing of Bradbury's reception in Bulgaria. It hadn't even occurred to me that Bradbury would be known in that country. But Young Jedi's Holocron has this fascinating account of Bradbury's critical reception in that country, complete with cold-war era distortions of fact, such as the time that Bradbury's house was burned to the ground. (Don't worry, never happened. But someone in Bulgaria thought it did. Apparently.)