Não informado. Transport economics. Interstate Commerce Commission, Bureau of Transport Economics and Statistics.
Citação do estilo Chicago (17ª ed.)Não informado. Transport Economics. Washington: Interstate Commerce Commission, Bureau of Transport Economics and Statistics.
Citação MLA (8ª ed.)Não informado. Transport Economics. Interstate Commerce Commission, Bureau of Transport Economics and Statistics.
Atenció: Aquestes cites poden no estar 100% correctes.