Nijeboer, P., H. Bontkes, C. Mulder, and G. Bouma. “Non-Celiac Gluten Sensitivity. Is It in the Gluten or the Grain?”. Journal of Gastrointestinal and Liver Diseases, Vol. 22, no. 4, Dec. 2013, pp. 435-40, https://jgld.ro/jgld/index.php/jgld/article/view/2013.4.12.