Hi Chris and Johan.
I don't know if the Seth books are translated to Dutch ( I am Danish) - but when I go to a book store in Denmark and ask about the Seth books, they do a search on the net for me. In short, a book store can tell you if they are available in Dutch, and where to buy them.
Book stores can also order them for you, in which case you could do the sums and see if that is cheaper for you than an online store based outside of the EU, which always means additional taxes for Europeans, and can make it quite expensive.
Remember to mention Jane Roberts, otherwise you might end up with some charlatan using Seth's name.
- happy hunting.