1. ASHENHURST R.L. Sorting and arranging. Theory of switching Rep. No. BL/7. Harvard Comput. Lab. Sect. 1 1953. ASHENHURST R.L. Sorting and arranging. Theory of switching Rep. No. BL/7. Harvard Comput. Lab. Sect. 1 1953.
2. Amphisbaenic Sorting
3. PL/I : Language specifications. IBM Form No. C28-6571. PL/I : Language specifications. IBM Form No. C28-6571.
4. Sorting techniques. IBM Form No. C20-1639. Sorting techniques. IBM Form No. C20-1639.