Joanna Rymarz, Anna Borucka, and Andrzej Niewczas. “Evaluation of Impact of the Operational and Technical Factors on Downtime of Municipal Buses Based on a Linear Regression Model ”. Communications - Scientific Letters of the University of Zilina, Vol. 23, no. 4, Oct. 2021, pp. A241-A247, doi:10.26552/com.C.2021.4.A241-A247.