Joanna Rymarz, Anna Borucka and Andrzej Niewczas 2021. 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. 23, 4 (Oct. 2021), A241-A247. DOI:https://doi.org/10.26552/com.C.2021.4.A241-A247.