Back by popular demand, Dell Sum-Doku combines the popular solving elements of Sudoku and Kakuro Cross Sums. Each volume contains easy, medium and hard solving levels designed to delight and challenge the mind. Detailed solving instructions are included. (Magazines are back issues shipped together in one package. Multiple value packs of one puzzle type may contain duplicates.) To assist with delivery to institutions be sure the recipient ID follows the last name and check institution policy on number of books allowed in a shipment.