Não informado. (1969). Airline management and marketing including american aviation. Ziff-Davis Aviation Division.
Lua i Stíl Chicago (17ú heag.)Não informado. Airline Management and Marketing Including American Aviation. Washington: Ziff-Davis Aviation Division, 1969.
Lua MLA (8ú heag.)Não informado. Airline Management and Marketing Including American Aviation. Ziff-Davis Aviation Division, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.