- citrulline amino acid. citrulline found in the following Zest for Life products.www.anyvitamins.com/citrulline-info.htm
- Citrulline. Photograph of Citrulline under the microscope Citrullinemicro.magnet.fsu.edu/aminoacids/pages/citruline.html
- Citrulline Elson M. Haas MD (Excerpted from Staying Healthy with Nutrition: The Complete Guide to Diet and Nutritional Medicine)www.healthy.net/library/books/haas/amino/cit.htm