I 50.145 
American Sero

rIistory eeotlomie soeial 

[IJ Leland1 'Va Ido G..8~ ]\,Tewton r..lfereness; Introdue


-tjm' to theAl\lel!ican offieial sources :for th 
econor:üe and soeial history of the Wor1d 
'Var. Ul26. 

L2J 
Hines 1 Walker D.: '.Var fIistory of Ameriean rai1, 
roads. 1928. 

S. Ports.: