E. L. Tilden, Snowden, J. M., Bovbjerg, M. L., Cheyney, M., Lapidus, J., Wiedrick, J., and Caughey, A. B.,
“Duration of low-risk, spontaneous active labor and second stage with minimal medical intervention”,
American Journal of Obstetrics and Gynecology, vol. 226, no. 1, pp. S512 - S513, 2022.