A variant of doubly linked list with items in sorted order and having two levels of additional links that span geometrically increasing distances. For a list with n items, the next level is a link from item i, 1 ≤ i ≤ n - ⌊ n ^1/3⌋, to item i + ⌊ i ^1/3⌋. At the top level, items 1³, 2³, 3³, ..., ⌊ n ^1/3⌋ ³ have backward links, that is, there is a link from item i³, 1 < i ≤ ⌊ n ^1/3⌋ ³, to item (i-1)³. Search, insert, and delete are O(n^1/3) worst case.