1. Industrial Dynamics;Forrester,1961
2. Optimal policies for a multi-echelon inventory problem;Clark;Mgmt. Sci.,1960
3. A dynamic, single-item, multi-echelon inventory model.;Clark,1958
4. Multi-echelon inventory theory - A retrospective;Clark,1992
5. Approximate solutions to a simple multi-echelon inventory problem;Clark,1962