I bought 5 books from the website www.sell-textbooks.com. I registered there and placed the order. Everything seemed to be ok, but the seller excused and told that two books were unavailable. He offered to change them for other books, which were similar to these ones. I agreed ad waited for the delivery. But I received only 3 books, and no sign of the other books. The seller kept silence and no idea where I could find the truth.