Emeryville, Calif. - Alibris, an online marketplace for new and second-hand books, on Tuesday announced a partnership with Blackwell U.K., a retailer of academic and professional books in the U.K. Under the deal, Blackwell customers will be able to search and order from Alibris' inventory of more than 75 million books, in addition to Blackwell's own catalog of more than 3 million books.