Subasinghe, Thilini Nadeeshani. “The Effectiveness of Entonox When Comparing to Pethidine for Labor Pain:: A Systematic Review”. Proceedings of the International Conference on Public Health 5, no. 2 (June 23, 2020): 8–18. Accessed August 5, 2025. https://proceedings.tiikmpublishing.com/index.php/icoph/article/view/378.