It's well known that ultra-nationalist governments thorough history has been always very strict with both immigration and emigration. Also ideas (books, movies

It's well known that ultra-nationalist governments thorough history has been always very strict with both immigration and emigration. Also ideas (books, movies, even music...) can influence a country even more than immigrants. Unsurprisingly, heavy censorship is very common dictatorships. It's interesting to look at what rich and poor countries import and export ideas, ranging from academic research, literature, art to popular movies...