Volume & Issue: Volume 3, Issue 10, May and June 2017 
2. Lagrangian Relaxation Method for the Step fixed-charge Transportation Problem

Pages 19-30

A. Mahmoodirad; S. Niroomand; M. Sanei; A. Sajedinejad

9. Centralized Cost Efficiency DEA Models

Pages 95-106

B. Rahmani Parchikolaei

10. Groups and Ultra-groups

Pages 107-116

Gh. Moghaddasi; P. Zolfaghari; B. Tolue Haghighi