1. Kommunikation mit Automaten;Petri;Schriften des Rheinisch-Westfalischen Institutes für Instrumentelle Mathematik an der Universität Bonn, Hft. 2, Bonn,1962
2. Information System Theory Project;Holt;Technical Report for Rome Air Development Center No. RADC-TR-68-305, prepared by Applied Data Research, Inc., Princeton, N. J.,1968
3. A new approach to optimization of sequencing decisions;Shapiro,1970
4. A. W. Holt and F. Commoner, Marked graphs and linear programming, unpublished notes.