Michalczyk, Michał, Dorota Torbé, and Andrzej Torbé. “Evaluation of the Impact of Various Methods of Analgesia onto Duration of Labor”. Journal of Education, Health and Sport 8, no. 8 (August 31, 2018): 951–958. Accessed July 27, 2024. https://apcz.umk.pl/JEHS/article/view/5880.