Actually kobieeli, he's written another book too (I saw that one at the old book store too, and will buy that one as soon as I can as well) called Shardik...

Here is a small list of the books he has written (I hope it's a complete list, I just did a search on google for it). Only Watership Down, The Plague Dogs and Shardik has been translated into Swedish though (for what I know).