@misc{Petrosyan_Petros_Upper,
 author={Petrosyan, Petros and Khachatryan, Nerses A.},
 howpublished={online},
 publisher={Изд-во НАН РА},
 title={Upper bounds for the maximum span in interval total colorings of graphs},
 type={Հոդված},
 keywords={Mathematics, Graph theory},
}