Shipments to the United States
Due to changes in U.S. customs regulations, all shipments to the United States are now subject to customs clearance.
This means that the recipient will be required to pay customs duties, as well as any applicable taxes and fees upon import.
Please also note that delivery may be delayed while the shipment is being processed by U.S. customs.
![Cover for Richard Guy · Unsolved Problems in Number Theory - Problem Books in Mathematics: Unsolved Problems in Intuitive Mathematics (Paperback Book) [3rd Ed. Softcover of Orig. Ed. 2004 edition] (2010)](https://imusic.b-cdn.net/images/item/original/281/9781441919281.jpg?richard-guy-2010-unsolved-problems-in-number-theory-problem-books-in-mathematics-unsolved-problems-in-intuitive-mathematics-paperback-book&class=scaled&v=1406834803)
![Cover for Richard Guy · Unsolved Problems in Number Theory (Hardcover Book) [3rd edition] (2004)](https://imusic.b-cdn.net/images/item/original/602/9780387208602.jpg?richard-guy-2004-unsolved-problems-in-number-theory-hardcover-book&class=scaled&v=1409722259)