Skačkauskienė, Ilona, Neringa Vilkaitė-Vaitonė, Jurgita Raudeliūnienė, and Vida Davidavičienė. 2016. “A Model for Measuring Passenger Loyalty”. Transport 31 (1):100–107. https://doi.org/10.3846/16484142.2015.1094748.