@ARTICLE{
author={Yero Ismael G,Rodriguez-Velazquez Juan A,Gutman Ivan},
year={2010},
title={Estimating the higher-order Randic index},
journal={CHEMICAL PHYSICS LETTERS},
volume={489},
number={1-3},
pages={118-120},
document_type={Article},
} 

@ARTICLE{
author={Gutman Ivan,Estrada Ernesto,Rodriguez-Velazquez Juan A},
year={2007},
title={On a graph-spectrum-based structure descriptor},
journal={CROATICA CHEMICA ACTA},
volume={80},
number={2},
pages={151-154},
document_type={Article},
}