Yamamoto K, Matsusue Y, Horita S, Minamiguchi M, Komatsu Y, Kirita T. Nicorandil-induced oral ulceration: report of 3 cases and review of the Japanese literature. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. 2011 Dec;112(6):754–9. doi: 10.1016/j.tripleo.2011.05.031.