  P. J. Federico used the term low-order for perfect squared squares with at
most 28 squares in their dissection. In 2010 low-order compound perfect squared
squares (CPSSs) were completely enumerated. Up to symmetries of the square and
its squared subrectangles there are 208 low-order CPSSs in orders 24 to 28. In
2012 the CPSSs of order 29 were completely enumerated, giving a total of 620
CPSSs up to order 29.
