BEHRENS, P. P.; LADEFOGED, T. . Udvikling af kontraktformer i den kollektive trafik. Proceedings from the Annual Transport Conference at Aalborg University, [S. l.], v. 8, n. 1, 2001. DOI: 10.5278/ojs.td.v8i1.4740. Disponível em: https://journals.aau.dk/index.php/td/article/view/4740. Acesso em: 7 may. 2024.