00290nam a2200109Ia 4500082002200000100001900022245008900041260002500130300001500155500000500170700000500175  a338.6042bB251.TI  aBarger, Harold  aTransportation industries 1889-1946; a study of output employment and productivityb  aNew YorkbNBERc1951  axvi, 288p.  a  a