Vaccaro, Rosa, Carola Severi, Giuditta Serrao, Marilia Carabotti, Arianna Casini, Piero Chirletti, and Paolo Onori. 2016. “Endocrine Cells Distribution in Human Proximal Small Intestine: An Immunohistochemical and Morphometrical Study”. Italian Journal of Anatomy and Embryology 121 (1):112-21. https://doi.org/10.13128/IJAE-18497.