Kownaklai J, Phanwichatkul T, Chaichan A, Lee A. Effectiveness of Spontaneous Pushing versus Valsalva Pushing in the Second Stage of Labor on Maternal and Neonatal Outcomes: A Systematic Review and Meta-analysis. PRIJNR [internet]. 2024 Mar. 21 [cited 2026 Sep. 19];28(2):407-20. available from: https://he02.tci-thaijo.org/index.php/PRIJNR/article/view/264145