TY JOUR TI Changes of the heavy metals content in Perca fluviatilis liver KW Republic of Khakassia KW Sorokaozerki tract KW Bolshoe Lake KW Stolbovoe Lake KW perch KW morphophysiological indicators KW liver index KW heavy metals JO Vestnik of Astrakhan State Technical University. Series: Fishing industry AU Devyatkin, G.. AU Kobceva, A.. PY 2023 IS 2023 PB Astrakhan State Technical University