1. FACULTY OF MEDICAL SCIENCES IN ZABRZE, MEDICAL UNIVERSITY OF SILESIA, ZABRZE, POLAND
2. ST. LUKE HOSPITAL, TARNÓW, POLAND
3. SPECIALIST HOSPITAL NAMED AFTER STEFAN ŻEROMSKI IN CRACOW, CRACOW, POLAND
4. MUNCIPAL HOSPITAL NO.4 IN GLIWICE, GLIWICE, POLAND