1. A Method for Determining the Optimal Division of Express and Local Rail Transit Service;Black;Highway Research Board,1962
2. Operating Strategies for Public Transportation Systems;Clarens,1972
3. Application of zone theory to a suburban rail transit network;Eisele;Traffic Quarterly,1968
4. Schedule Evaluation and Zone Structuring for Urban Rail Commuter Service on Planned and Existing Routes;Ghoneim,1982
5. Optimum Zone Configuration for Planned Urban Commuter Rail Lines;Ghoneim,1983