Phumdoung S, Morkruengsai S, Tachapattarakul S, Lawantrakul J, Junsuwan P. Effect of the Prince of Songkla University Locked-Upright Position on the Duration, Pain and Comfort of Second-Stage Labor in Primiparous Women. PRIJNR [internet]. 2013 Feb. 6 [cited 2026 Sep. 20];14(2):112-21. available from: https://he02.tci-thaijo.org/index.php/PRIJNR/article/view/6297