Cita APA (7a ed.)

Heardman, H., & Ebner, M. (1982). Relaxation and exercise for natural childbirth (5th ed.). Churchill Livingstone.

Cita Chicago Style (17a ed.)

Heardman, Helen, y Maria Ebner. Relaxation and Exercise for Natural Childbirth. 5th ed. Edinburgh: Churchill Livingstone, 1982.

Cita MLA (9a ed.)

Heardman, Helen, y Maria Ebner. Relaxation and Exercise for Natural Childbirth. 5th ed. Churchill Livingstone, 1982.