@ARTICLE{
author={Gutman Ivan,Ghorbani Modjtaba},
year={2012},
title={Some properties of the Narumi-Katayama index},
journal={APPLIED MATHEMATICS LETTERS},
volume={25},
number={10},
pages={1435-1438},
document_type={Article},
} 

@ARTICLE{
author={Diudea Mircea V,Ilic Aleksandar,Ghorbani Modjtaba,Ashrafi Ali Reza},
year={2010},
title={Cluj CJ and PIv Polynomials},
journal={CROATICA CHEMICA ACTA},
volume={83},
number={3},
pages={283-289},
document_type={Article},
}