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.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.