Khoiria, A., & Sastrowijoto, S. (2023). A rare cause of esophageal stricture: undifferentiated carcinoma of the lower esophagus. International Journal of Otorhinolaryngology and Head and Neck Surgery, 9(2), 189–193. https://doi.org/10.18203/issn.2454-5929.ijohns20230107