TY JOUR TI ECONOMETRIC ANALYSIS OF MUTUAL TRADE BETWEEN RUSSIA AND CHINA KW Russia KW China KW economic development KW cooperation KW export KW import KW adaptive polynomial model KW mutual trade KW foreign trade turnover JO Science & World AU Tsvil, M.M. AU Gavrish, V.A. PY 2023 IS 2023 PB LLC "Perspektiva"