Sorting n objects with a k-sorter
Richard Beigel, John T. Gill · IEEE Transactions on Computers · 1990
A k-sorter is a device that sorts k objects in unit time. The complexity of an algorithm that uses a k-sorter is defined as the number of applications of the k-sorter. In this measure, the complexity of sorting n objects is between n log n/k log k and 4n log n/k log k, up to first-order terms in n and k.>