  In-place associative integer sorting technique was developed, improved and
specialized for distinct integers. The technique is suitable for integer
sorting. Hence, given a list S of n integers S[0...n-1], the technique sorts
the integers in ascending or descending order. It replaces bucket sort,
distribution counting sort and address calculation sort family of algorithms
and requires only constant amount of additional memory for storing counters and
indices beside the input list. The technique was inspired from one of the
ordinal theories of "serial order in behavior" and explained by the analogy
with the three main stages in the formation and retrieval of memory in
cognitive neuroscience: (i) practicing, (ii) storing and (iii) retrieval.
  In this study in-place associative permutation technique is introduced for
integer key sorting problem. Given a list S of n elements S[0...n-1] each have
an integer key in the range [0,m-1], the technique sorts the elements according
to their integer keys in O(n) time using only O(1) amount of memory if m<=n. On
the other hand, if m>n, it sorts in O(n+m) time for the worst, O(m) time for
the average (uniformly distributed keys) and O(n) time for the best case using
O(1) extra space.
