[1]
D. Zalar, R. Ušpalytė-Vitkūnienė, D. Rebolj, and M. Lep, “A methodological framework for measuring the level of convenience of transport ticketing systems”, Transport, vol. 33, no. 4, pp. 1005–1016, Dec. 2018, doi: 10.3846/16484142.2017.1300783.