Aberle, W. H. G. (1978). Economic prospects for railways: Report of the thirty-ninth round table on Transport Economics, held in Paris on 19th and 20th October, 1977.. Paris: European Conference of Ministers of Transport.
Dyfyniad Arddull ChicagoAberle, W. Hamm G. Economic Prospects for Railways: Report of the Thirty-ninth Round Table On Transport Economics, Held in Paris On 19th and 20th October, 1977.. Paris: European Conference of Ministers of Transport, 1978.
Dyfyniad MLAAberle, W. Hamm G. Economic Prospects for Railways: Report of the Thirty-ninth Round Table On Transport Economics, Held in Paris On 19th and 20th October, 1977.. Paris: European Conference of Ministers of Transport, 1978.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.