1. Wulf, Cohen, Coowin, Jones, Levin, Pierson, Pol lach, Hydra: The Kernel of a Multiprogramming System, Technical Report, Computer Science Department, Carnegie-Mellon University.
2. David L. Parnas, Information Distribution Aspects of Design Methodology, Proceedings of the 1971 IFIP Congress, Booklet TA/3, 26-30.
3. E.W. Dijkstral The Structure of the T.H.E. Multiprogramming System, Communications of the ACM, vol 11, no. 5, May 1968, 341–346.
4. E. W Dijkstra, Complexity controlled by Hierarchical Ordering of Function and Variability, Software Engineering, NATO.
5. David L. Parnas, On the Criteria to be Used in Decomposing Systems into Modules, Communications of the ACM, vol. 15, no. 12, December 1972, 1053–1058.