I collect vegetarian cookbooks from around the world. I prefer them published locally, in the local language, and concerning a traditional local vegetarian cuisine or a vegetarian adaptation of a traditional cuisine. I have to give in on one preference or another regularly. But I only give in on vegetarian as a last resort, because that's what absolutely determines whether there is any chance I will ever cook and eat something from a given cookbook.
We keep track of our books in LibraryThing. I think it might be fair to say that LibraryThing is a site for people who accumulate books, rather than collect books. It does not so much concentrate on conditions and editions as finding books to read and things about the books you read by connecting with other people through their libraries. A social site for readers, mediated by their books.
By default, libraries on LibraryThing are public. Anyone can be like Thomas Jefferson or Martha Rosler. Some users opt to make their library private. Others wish for features that would let them hide certain aspects, such as some tags or comments. Personally, I reason that if you know me you can come over to my house and see my books on the shelves already and if you do not then all you know is that someone somewhere has this particular set of books.
Using the LibraryThing database for our library, I can mash-up with Google Maps to draw a map of where our veggie cookbooks were published. It's a little trickier than it might be geocoding library information, since records to not explicitly make some distinctions, like Cambridge, Massachusetts versus Cambridge, Cambridgeshire. (You tell by the publisher.) The gory details are here. It is fairly easy to make a new map from any set of books with an interesting geographical distribution; for instance, here is a widely translated author.
One thing that is obvious from the map is that I have not managed to find any cookbooks from Africa. There are cookbooks of North African vegetarian cuisine published in France. And vegetarian adaptations of sub-Saharan cooking from the USA. But not much from the continent itself, at least that I can find. I have seen a book written by the owners of a popular South African vegetarian restaurant, but it is apparently hard to find even in that country.
Update: The Globe reports on an important collection of vegetarian books and ephemera just acquired by the Schlesinger Library. There is no mention of anything in foreign languages, though. The closest thing I have to anything rare (as opposed to unusual) is Yiddish cookbooks from New York in the '30s. (h/t PhiloBiblos)