The effect of inflatable obstetric belts in nulliparous pregnant women receiving patient-controlled epidural analgesia during the second stage of labor. - Kim, Jong-Woon; Kim, Yoon Ha; Cho, Hye Yon; Shin, Hee-Young; Shin, Jong Chul; Choi, Sea Kyung; Lee, Keun-Young; Song, Ji-Eun; Lee, Pil-Ryang (Journal of Maternal-Fetal & Neonatal Medicine, 2013)