@ARTICLE{
author={Sedlar Jelena,Stevanovic Dragan P,Vasilyev Alexander},
year={2015},
title={On the inverse sum indeg index},
journal={DISCRETE APPLIED MATHEMATICS},
volume={184},
number={},
pages={202-212},
document_type={Article},
} 

@ARTICLE{
author={Vasilyev Alexander,Darda Ratko,Stevanovic Dragan P},
year={2014},
title={Trees of Given Order and Independence Number with Minimal First Zagreb Index},
journal={MATCH-COMMUNICATIONS IN MATHEMATICAL AND IN COMPUTER CHEMISTRY},
volume={72},
number={3},
pages={775-782},
document_type={Article},
}