Qiu, Shaotian, et al. “The Development and Validation of a Nomogram for Predicting Cancer-Specific Survival and a Risk Stratification System for Patients With Primary Gastrointestinal Melanoma”. Turkish Journal of Gastroenterology, vol. 34, no. 8, Jan. 2023, pp. 850-8, doi:10.5152/tjg.2023.22711.