Locklin, D. P. (1938). Economics of transportation (Rev. ed.). Business publications, inc..
Chicago-viite (17. p.)Locklin, D. Philip. Economics of Transportation. Rev. ed. Chicago: Business publications, inc., 1938.
MLA-viite (8. p.)Locklin, D. Philip. Economics of Transportation. Rev. ed. Business publications, inc., 1938.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.