Tecellioglu, M., and C. Cankaya. “Evaluation of Macular and Retinal Nerve Fiber Layer Thicknesses in Episodic-Type Cluster Headache Patients by Optical Coherence Tomography”. Annals of Medical Research, vol. 26, no. 3, May 2021, pp. 0489-94, http://www.annalsmedres.org/index.php/aomr/article/view/1319.