Sanatkhani, M., Pakfetrat, A., & Shirzadeh, A. R. "Oral ulcers among patients referred to oral medicine department of Mashhad Dental School in a period of 6 years", Iranian Journal of Otorhinolaryngology, 21, 56, 2009, 89-94. doi: 10.22038/ijorl.2009.705