Hagenberg, R. (1989). Karel Appel: Dupe of Being / Edited by Roland Hagenberg. Ed. Lafayette.
Lua i Stíl Chicago (17ú heag.)Hagenberg, Roland. Karel Appel: Dupe of Being / Edited by Roland Hagenberg. o.O.: Ed. Lafayette, 1989.
Lua MLA (8ú heag.)Hagenberg, Roland. Karel Appel: Dupe of Being / Edited by Roland Hagenberg. Ed. Lafayette, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.