Lou YY. Hamman’s syndrome: spontaneous pneumomediastinum and subcutaneous emphysema during second stage of labour. Int J Reprod Contracept Obstet Gynecol [Internet]. 2017 May 25 [cited 2025 Oct. 4];6(6):2622-4. Available from: https://www.ijrcog.org/index.php/ijrcog/article/view/2751