Daniel Silva has two sets of Gabriel Allon books: Books 1-4 and Books 5-8.
These are Penguin and not couponable in the US, but are couponable in Singapore, and probably a few other places.
http://store.kobobooks.com/en-US/ebo...lon-novels-1-4
http://store.kobobooks.com/en-US/ebo...lon-novels-5-8