Yeomans ER, Hauth JC, Gilstrap LC, Strickland DM (March 1985). "Umbilical cord pH, PCO2, and bicarbonate following uncomplicated term vaginal deliveries". American Journal of Obstetrics and Gynecology. 151 (6): 798–800. doi:10.1016/0002-9378(85)90523-x. PMID3919587.
Yeomans ER, Hauth JC, Gilstrap LC, Strickland DM (March 1985). "Umbilical cord pH, PCO2, and bicarbonate following uncomplicated term vaginal deliveries". American Journal of Obstetrics and Gynecology. 151 (6): 798–800. doi:10.1016/0002-9378(85)90523-x. PMID3919587.