Haas, G. (1969). Essay. Metzler.
Lua i Stíl Chicago (17ú heag.)Haas, Gerhard. Essay. Stuttgart: Metzler, 1969.
Lua MLA (8ú heag.)Haas, Gerhard. Essay. Metzler, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)