TY  - JOUR
AU  - faezy razi, farshad
AU  - Shadloo, Naeimeh
TI  - A Hybrid Grey based Two Steps Clustering and Firefly Algorithm for Portfolio Selection
JO  - Journal of Optimization in Industrial Engineering
VL  - 10
IS  - 22
SP  - 49
EP  - 59
PY  - 2017
DO  - 10.22094/joie.2017.276
ER  -