Lanzillotti, R. F. (1953). The Washington tourist survey, 1952: A summary report of nonresident tourist travel, 1947-1952.
Lua i Stíl Chicago (17ú heag.)Lanzillotti, Robert Franklin. The Washington Tourist Survey, 1952: A Summary Report of Nonresident Tourist Travel, 1947-1952. Pullman, 1953.
Lua MLA (8ú heag.)Lanzillotti, Robert Franklin. The Washington Tourist Survey, 1952: A Summary Report of Nonresident Tourist Travel, 1947-1952. 1953.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.