@base . a ; "2664-4991" ; . "Ukraine" . a . a , ; "Researches in mathematics (Online)" . a ; . a ; "20240218171243.382474"^^ ; ; . . , ; "Researches in mathematics." ; ; ; ; ; ; ; "Researches in mathematics (Online)" , "Researches in mathematics." ; ; "https://vestnmath.dnu.dp.ua" .