Heardman, h. (1987). Melahirkan secara alamiah (A way to natural childbirth). EGC.
Lua i Stíl Chicago (17ú heag.)Heardman, helen. Melahirkan Secara Alamiah (A Way to Natural Childbirth). EGC, 1987.
Lua MLA (9ú heag.)Heardman, helen. Melahirkan Secara Alamiah (A Way to Natural Childbirth). EGC, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.