List of Articles Grey System Theory Open Access Article Abstract Page Full-Text 1 - A Primal Simplex Algorithm for Solving Linear Programming Problem with Grey Cost Coefficients S.H. Nasseri A. Yazdani D. Darvishi Salokolaei Open Access Article Abstract Page Full-Text 2 - Portfolio selection by Using Multi Attribute Decision Making based on grey relational analysis and linear programming A. Asghar Anvari Rostami Mahdis Taghavi M. Ebrahim Aghababaei