ScienceDirect (Online service), Said, H. M., & Ghishan, F. K. (2018). Physiology of the gastrointestinal tract (Sixth edition.). Academic Press, an imprint of Elsevier.
Chicago Style (17th ed.) CitationScienceDirect (Online service), Hamid M. Said, and Fayez K. Ghishan. Physiology of the Gastrointestinal Tract. Sixth edition. London: Academic Press, an imprint of Elsevier, 2018.
MLA (9th ed.) CitationScienceDirect (Online service), et al. Physiology of the Gastrointestinal Tract. Sixth edition. Academic Press, an imprint of Elsevier, 2018.
Warning: These citations may not always be 100% accurate.