Index Translationum
This useful site contains a database of books translated and published in about 100 of the UNESCO states since 1979 and totalling more than 1.500,000 entries in all disciplines : literature, social and human sciences, natural and exact sciences, art, history and so on. It also provides some surprising statistics about the world's most translated authors.
http://databases.unesco.org/xtrans/xtra-form.html