Pinto HC, Portela-Gomes GM, Grimelius L, Kohnert KD, de Sousa JC, Albuquerque MA. The distribution of endocrine cell types of the gastrointestinal mucosa in genetically diabetic (db/db) mice. Gastroenterology. 1995 Apr;108(4):967–74. doi: 10.1016/0016-5085(95)90191-4. PMID: 7698612.