U.S. National Library of Medicine. (24 July 2015 updated.) Gastrin Blood Test. Available online at https://medlineplus.gov/ency/article/003697.htm. Accessed March 2017.

Mayo Medical Laboratories. Gastrin, Serum. Available online at http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/8512. Accessed March 2017.

Devkota BP. (17 January 2014 updated.) Gastrin. Available online at http://emedicine.medscape.com/article/2089092-overview#a4. Accessed March 2017.

Healthwise Staff. (9 September 2014 updated.) Gastrin. Available online at http://www.webmd.com/digestive-disorders/gastrin#1. Accessed March 2017.

Pagana, Kathleen D., Pagana, Timothy J., and Pagana, Theresa N. (© 2015). Mosby's Diagnostic and Laboratory Test Reference. 12th Edition: Mosby, Inc., Saint Louis, MO. Pp 456-457.

Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 471-472.

Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC Press, Washington, DC. Pp 301, 303.

Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests, Fourth Edition.  Saunders Elsevier, St. Louis, Missouri. Pp 432-435.

Hurd, R. (2007 October 24). Gastrin. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003697.htm. Accessed on 10/11/08.

Stone, C. (2008 February 20, Updated). Zollinger-Ellison syndrome. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000325.htm. Accessed on 10/11/08.

Livstone, E. (2007 December, Revised). Pancreatic Endocrine Tumors. Merck Manual Home Edition [On-line information]. Available online at http://www.merck.com/mmhe/sec09/ch131/ch131l.html#sec09-ch131-ch131l-950. Accessed on 10/11/08.

(2008 April). Your Digestive System and How it Works. National Digestive Diseases Information Clearinghouse [On-line information]. Available online at http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/. Accessed on 10/11/08.

Meikle, A. W. (2008 July, Updated). Zollinger-Ellison Syndrome – Gastrinoma. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/OncologicDz/NeuroendocrineTumors/Gastrinoma.html#. Accessed on 10/18/08.

Bonheur, J. and Nachimuthu, S. (2006 June 27). Gastrinoma. EMedicine [On-line information]. Available online at http://www.emedicine.com/med/TOPIC2678.HTM. Accessed on 10/11/08.

Dugdale, D. (Updated 2011 August 5). Gastrin - blood test. MedlinePlus Medical Encyclopedia. [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003697.htm. Accessed October 2012.

(© 1995-2012). Gastrin, Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/8512. Accessed October 2012.

(Revised 2012 January 13). How is pancreatic cancer diagnosed? American Cancer Society [On-line information]. Available online at http://www.cancer.org/Cancer/PancreaticCancer/DetailedGuide/pancreatic-cancer-diagnosis. Accessed October 2012.

Bishnu D. (Updated 2012 April 10). Gastrin. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/2089092-overview. Accessed October 2012.

(Modified 2012 February 6). General Information About Pancreatic Neuroendocrine Tumors (Islet Cell Tumors). National Cancer Institute [On-line information]. Available online at http://www.cancer.gov/cancertopics/pdq/treatment/isletcell/patient/. Accessed October 2012.

Bonheur, J. and Nachimuthu, S. (Updated 2012 January 25). Gastrinoma. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/184332-overview. Accessed October 2012.

(Updated 2012 May 10). Zollinger-Ellison Syndrome. National Institute of Diabetes and Digestive and Kidney Diseases [On-line information]. Available online at http://digestive.niddk.nih.gov/ddiseases/pubs/zollinger/. Accessed October 2012.

Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 478-479.