TY JOUR TI FEATURES OF PERFORATIVE GASTRODUODENAL ULCER IN CANCER PATIENTS KW perforative gastroduodenal ulcer KW predictive model KW cancer patients JO CASPIANJOURNALOF MEDICINE AND PHARMACY AU Panin, S.. AU Kovalenko, N.. AU Postolov, M.. AU Suvorov, V.. PY 2021 IS 2 PB Astrakhan State Medical University