@ARTICLE{
author={Ali Akbar,Zhong Lingping,Gutman Ivan},
year={2019},
title={Harmonic Index and its Generalizations: Extremal Results and Bounds},
journal={MATCH-COMMUNICATIONS IN MATHEMATICAL AND IN COMPUTER CHEMISTRY},
volume={81},
number={2},
pages={249-311},
document_type={Review},
} 

@ARTICLE{
author={Gutman Ivan,Zhong Lingping,Xu Kexiang},
year={2014},
title={Relating the ABC and harmonic indices},
journal={JOURNAL OF THE SERBIAN CHEMICAL SOCIETY},
volume={79},
number={5},
pages={557-563},
document_type={Article},
}