Jakub Horák, Petr Šuleř, and Jaromír Vrbka. “Analysis of Transportation Companies in the Czech Republic by the Kohonen Networks – Identification of Industry Leaders”. Communications - Scientific Letters of the University of Zilina, Vol. 23, no. 1, Jan. 2021, pp. A32-A43, doi:10.26552/com.C.2021.1.A32-A43.