Khajavi, M., N. Ahmady Roozbahany, S. Shomali, and M. Hosseynrezai Mahani. “Refractory Sinonasal Hemangiopericytoma: Rapid Recurrence or Growth of Residual Tumor”. Journal of Otorhinolaryngology and Facial Plastic Surgery, vol. 1, no. 1, Sept. 2015, pp. pp. 21-24, doi:10.22037/orlfps.v1i1.9391.