TY JOUR TI THE ORIGIN OF KONDRATYEV WAVES HAS BEEN PROVEN, BUT WHAT NEXT KW basis KW superstructure KW stability KW crisis KW (import) KW export KW ATS KW statics KW dynamics KW (modeling) JO Science & World AU Yarmolatiy, V.A. PY 2021 IS 2021 PB LLC "Perspektiva"