"Duke University Press" vs "Duke University Press Books"
Their web site says Duke University Press (see also here) and the copyright page from the amazon.com "Look inside" option says Duke University Press. Googling "Duke University Press Books" suggests to me that the addition of "Books" is extra, not part of the official name, such as saying "Dover Publishers Books" rather than "Dover Publishers". Thus, I think Duke University Press is what you want to use.