APA (7e ed.) Bronvermelding

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

Chicago (17e ed.) Bronvermelding

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

MLA (9e ed.) Bronvermelding

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