Fabry, H. (1977). Glwlym - hms. Kohlhammer.
Lua i Stíl Chicago (17ú heag.)Fabry, Heinz-Josef. Glwlym - Hms. Stuttgart [u.a.]: Kohlhammer, 1977.
Lua MLA (8ú heag.)Fabry, Heinz-Josef. Glwlym - Hms. Kohlhammer, 1977.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.