Mathematical modeling of multimodal transportation in Ukraine using methods of the graph theoryIryna Perevozova, Svitlana Minakova, Khrystyna Obelnytska, Liliya Mykhailyshyn and Olena MorozovaE3S Web Conf., 255 (2021) 01030DOI: https://doi.org/10.1051/e3sconf/202125501030