Mark, R. (1994). The joy of flying. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Mark, Robert. The Joy of Flying. McGraw-Hill, 1994.
Lua MLA (8ú heag.)Mark, Robert. The Joy of Flying. McGraw-Hill, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.