Use effectiveness of the Creighton model ovulation method of natural family planning.
J Obstet Gynecol Neonatal Nurs. 1994 May;23(4):303-9. doi: 10.1111/j.1552-6909.1994.tb01881.x.
J Obstet Gynecol Neonatal Nurs. 1994.
PMID: 8057183