Hywel, D. (1978). Cardiology.
Lua i Stíl Chicago (17ú heag.)Hywel, Davies. Cardiology. 1978.
Lua MLA (9ú heag.)Hywel, Davies. Cardiology. 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)