APA

U.S. Departament of Transportation Federal Highway Administration, . (1998). Highway statistics 1997. Washington: [Editor no identificado].

Chicago

U.S. Departament of Transportation Federal Highway Administration, . 1998. Highway statistics 1997. Washington: [Editor no identificado].

Harvard

U.S. Departament of Transportation Federal Highway Administration, . (1998). Highway statistics 1997. Washington: [Editor no identificado].

MLA

U.S. Departament of Transportation Federal Highway Administration, . Highway statistics 1997. Washington: [Editor no identificado]. 1998.