List of Articles Naeimeh Shadloo Article 1 - A Hybrid Grey based Two Steps Clustering and Firefly Algorithm for Portfolio Selection 20.1001.1.22519904.2017.10.22.5.0 10.22094/joie.2017.276 farshad faezy razi Naeimeh Shadloo Journal of Optimization in Industrial Engineering , Issue 22 , Year , Autumn 2017