@ARTICLE{
author={Petrovic David T,Kricak Lazar M,Negovanovic Milanka N,Milanovic Stefan V,Markovic Jovan R,Simic Nikola Z,Stamenic Ljubisav S},
year={2019},
title={Valorization of Non-Balanced Coal Reserves in Serbia for Underground Coal Gasification},
journal={THERMAL SCIENCE},
volume={23},
number={6},
pages={4067-4081},
document_type={Article},
} 

@ARTICLE{
author={Petrovic David T,Djukanovic Dusko N,Petrovic Dragana M,Svrkota Igor M},
year={2019},
title={Contribution to Creating a Mathematical Model of Underground Coal Gasification Process},
journal={THERMAL SCIENCE},
volume={23},
number={5},
pages={3275-3282},
document_type={Article},
}