Abdullah, Muhammad. “Recurrent Askin`s Tumor: Ewing`s Sarcoma Primitive Neuroectodermal Tumor of Chest Wall”. Annals of King Edward Medical University 9, no. 4 (July 13, 2016). Accessed April 19, 2024. https://www.annalskemu.org/journal/index.php/annals/article/view/1358.