Bakker, Jannet J.  H., Verhoeven, Corine J.  M., Janssen, Petra F., van Lith, Jan M., van Oudgaarden, Elizabeth D., Bloemenkamp, Kitty W.  M., Papatsonis, Dimitri N.  M., Mol, Ben Willem J., van der Post, Joris A.  M., "Outcomes after internal versus external tocodynamometry for monitoring labor", Obstetrical and Gynecological Survey, 2010