Litwińczuk, M., J. Szydełko, and M. Szydełko. “The Diagnostic and Therapeutic Difficulties in Management With Pheochromocytoma in Pregnancy – a Review”. Journal of Education, Health and Sport, vol. 9, no. 9, Sept. 2019, pp. 543-59, https://apcz.umk.pl/JEHS/article/view/7476.