Heardman, H., & Ebner, M. (1982). Relaxation and exercise for natural childbirth (5th ed.). Churchill Livingstone.
Lua i Stíl Chicago (17ú heag.)Heardman, Helen, agus Maria Ebner. Relaxation and Exercise for Natural Childbirth. 5th ed. Edinburgh: Churchill Livingstone, 1982.
Lua MLA (9ú heag.)Heardman, Helen, agus Maria Ebner. Relaxation and Exercise for Natural Childbirth. 5th ed. Churchill Livingstone, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.