APA

Estados Unidos, . (1938). Descriptions of airports and landing fields in the United States. Washington: United States Government Printing Office.

Chicago

Estados Unidos, . 1938. Descriptions of airports and landing fields in the United States. Washington: United States Government Printing Office.

Harvard

Estados Unidos, . (1938). Descriptions of airports and landing fields in the United States. Washington: United States Government Printing Office.

MLA

Estados Unidos, . Descriptions of airports and landing fields in the United States. Washington: United States Government Printing Office. 1938.