GRZELEC, Krzysztof; KOŁODZIEJSKI, Hubert; WYSZOMIRSKI, Olgierd. Directions of tariff and ticket integration of public transport in the metropolitan area Gdańsk-Gdynia-Sopot the Pomeranian Voivodeship. Transport Economics and Logistics, [S. l.], v. 76, p. 155–165, 2018. DOI: 10.26881/etil.2018.76.13. Disponível em: https://czasopisma.bg.ug.edu.pl/index.php/znetil/article/view/2917. Acesso em: 22 jul. 2024.