Metelski, J., A. Metelska, D. Sereda, H. Nieścior, and M. Szwed. “Zollinger-Ellison Syndrome - Review”. Journal of Education, Health and Sport, vol. 12, no. 8, Aug. 2022, pp. 523-32, doi:10.12775/JEHS.2022.12.08.055.