Thanks for the interest on Verniana and Paganel's books.
Combined shipping is not possible directly on the website, because the current system is not prepared for that. We're working on a new shopping website that will be available soon and that new system will correct this problem.
For the time being, even if combined shipping is not possible automatically via the website, you can write to me directly and we'll gladly offer combined shipping for you, so you can pay just for one time for receiving all the books you want. We have made that in the past for other people that were interested in our books.
Please drop me a line at ari...@gmail.com
and tell me what books you're interested in.