Gilles, W., & Ruhrberg, K. (1962). Werner Gilles: Karl Ruhrberg. Bongers.
Lua i Stíl Chicago (17ú heag.)Gilles, Werner, agus Karl Ruhrberg. Werner Gilles: Karl Ruhrberg. Recklinghausen: Bongers, 1962.
Lua MLA (8ú heag.)Gilles, Werner, agus Karl Ruhrberg. Werner Gilles: Karl Ruhrberg. Bongers, 1962.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.