Fatima Ayub, Nilofar Mustafa, Pakeeza Aslam, Rehana Kanwal, Qurutulain Mushtaq, Shazia Tufail 2023. Frequency of Perineal Trauma in Women Undergoing Spontaneous vs Directed Valsalva Type Pushing in Labour. Pakistan Journal of Medical & Health Sciences. 16, 11 (Jan. 2023), 730. DOI:https://doi.org/10.53350/pjmhs20221611730.